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NEWS & UPDATES
(Gould BRS 2019 Neurotransmitters and Pathways) V1 PDF
(Le FA 1 2021 Respiratory) V1 PDF
(Dudek HY 2014, Harrell LIR 2018, Goldberg MRS 2016, Whitaker 2016, Lymphatic System) V1 PDF
(Goldberg MRS Anatomy 2016 Spinal Nerves) V1 PDF
(Goldberg MRS Anatomy 2016 Cranial Nerves) V1 PDF
(Goldberg MRS Anatomy 2016 Autonomic Nervous System) V1 PDF
TOC
OVERVIEW
GENERAL
SYSTEMS
FASCIA_SEROSA_MENINGES - MEMBRANES
SKELETAL
ARTICULAR
MUSCULAR
INTEGUMENTARY
SENSES
NERVOUS
CIRCULATORY
HEART
ARTERIES
VEINS
LYMPHATICS
VISCERAL
RESPIRATORY
DIGESTIVE
ENDOCRINE
GENITO-URINARY
REGIONS
LIMBS
DEVELOPMENT OF THE LIMBS
UPPER LIMB
BONES OF THE UPPER LIMB
JOINTS & LIGAMENTS OF THE UPPER LIMB
MUSCLES OF THE UPPER LIMB
VESSELS OF THE UPPER LIMB
NERVES OF THE UPPER LIMB
REGIONS OF THE UPPER LIMB
LOWER LIMB
BONES OF THE LOWER LIMB
JOINTS & LIGAMENTS OF THE LOWER LIMB
MUSCLES OF THE LOWER LIMB
VESSELS OF THE LOWER LIMB
NERVES OF THE LOWER LIMB
REGIONS OF THE LOWER LIMB
HEAD NECK BACK
HEAD
NECK
CRANIUM - SKULL
CRANIUM IN GENERAL
DEVELOPMENT OF THE CRANIUM
BONES OF THE CRANIUM
BONES OF THE FACE
CAVITIES & FORAMINA
MANDUCATORY APPARATUS
TEMPOROMANDIBULAR JOINT
MUSCLES OF MASTICATION
TEETH
BACK
BACK IN GENERAL
VERTEBRAL COLUMN
MUSCLES OF THE BACK
HEAD & NECK
HEAD & NECK : TOPOGRAPHY & MUSCLES
SUPERFICIAL TOPOGRAPHY OF THE HEAD & NECK
MUSCLES OF THE HEAD
MUSCLES & ANTERIOR SPACES OF THE NECK
HEAD & NECK : VESSELS & NERVES
ARTERIES OF THE HEAD & NECK
VEINS OF THE HEAD & NECK
LYMPHATICS OF THE HEAD & NECK
CERVICAL SPINAL NERVES - CERVICAL SYMPATHETIC TRUNK
HEAD & NECK : VISCERA
DEVELOPMENT OF THE BRANCHIAL APPARATUS
MOUTH - ORGAN OF TASTE
SALIVARY GLANDS
PHARYNX
LARYNX
THYROID & PARATHYROID GLANDS
THYMUS
SENSORY ORGANS
EYE - ORGAN OF VISION
EAR - ORGAN OF HEARING & BALANCE
NOSE - ORGAN OF OLFACTION
MOUTH - ORGAN OF TASTE
SKIN - ORGAN OF TOUCH
THORAX & ABDOMEN
THORAX
THORAX & ABDOMEN : VESSELS & NERVES
ABDOMEN
NEUROANATOMY
OVERVIEW OF THE NERVOUS SYSTEM
NEURO-EMBRYOLOGY
NEURO-HISTOLOGY
MENINGES, VENTRICLES & CSF
BLOOD SUPPLY OF THE CNS
SENSORY SYSTEM
MOTOR SYSTEM
SPINAL_CORD
MORPHOLOGY OF THE SPINAL CORD
TRACTS OF THE SPINAL CORD
ASCENDING TRACTS OF THE SPINAL CORD - SENSORY
DESCENDING TRACTS OF THE SPINAL CORD - MOTOR
ASCENDING & DESCENDING SPINAL PATHWAYS FOR VISCERAL FUNCTIONS
INTEGRATIVE PATHWAYS OF THE SPINAL CORD
LESIONS_OF_THE_SPINAL_CORD
SEGMENTS OF THE SPINAL CORD
8 C
12 T
5 L
5 S
1 Co
DEVELOPMENT OF THE SPINAL CORD
BLOOD SUPPLY OF THE SPINAL CORD
SPINAL_NERVES
LESIONS
AUTONOMIC_NERVOUS_SYSTEM
SYMPATHETIC - VISCEROMOTOR & VISCEROSENSORY
PARASYMPATHETIC - VISCEROMOTOR & VISCEROSENSORY
ENTERIC
HINDBRAIN = RHOMBENCEPHALON = MYELENC. + METENC.
METENC. = PONS + 4TH VENT. + CEREBELLUM
BRAINSTEM - CNs + RF + BREATHING = MEDULLA + PONS + MIDBRAIN
MEDULLA OBLONGATA = MYELENC.
PONS
MESENCEPHALON = MIDBRAIN
LESIONS_OF_THE_BRAINSTEM
CEREBELLUM
CRANIAL_NERVES
0 TERMINAL
I OLFACTORY - OLFACTORY SYSTEM - SMELL - CHEMICAL SENSE
III OCULOMOTOR
IV TROCHLEAR
VI ABDUCENS
EYE MOVEMENT = III + IV + VI - OPTOMOTOR SYSTEM
II OPTIC - VISUAL_SYSTEM - VISION
V TRIGEMINAL - TRIGEMINAL_SYSTEM
VIII VESTIBULO-COCHLEAR - AUDITORY SYSTEM - HEARING - VESTIBULAR SYSTEM - BALANCE
VII FACIAL - EXPRESSION
IX GLOSSOPHARYNGEAL - ORAL SENSATION, TASTE & SALIVATION
X VAGUS
GUSTATORY SYSTEM = VII + IX + X - CHEMICAL SENSE
XI ACCESSORY - SHOULDER ELEVATION & HEAD-TURNING
XII HYPOGLOSSAL - TONGUE MOVEMENT
BRAIN = ENCEPHALON = BRAINSTEM + CEREBELLUM + DIENC. + HYPOPHYSIS + CEREBRUM
PROENC. = FOREBRAIN = TELENC. + DIENC.
DIENCEPHALON = EPITHALAMUS + (DORSAL) THAL. + HYPOTHAL. + SUBTHAL. (VENTRAL THAL.) + THIRD VENT. & ASSOCIATED STRUCTURES
THALAMUS
INTERNAL CAPSULE
HYPOTHALAMUS & HYPOPHYSIS
CEREBRUM = TELENC. = CEREBRAL HEMISPHERES + BASAL NUCLEI + LATERAL VENT. + CEREBRAL CORTEX + WHITE MATTER + LIMBIC SYSTEM
LIMBIC SYSTEM
BASAL NUCLEI
CEREBRAL CORTEX
NEUROTRANSMITTERS & PATHWAYS - CHEMICAL NEUROANATOMY
REFERENCES
TOC
OVERVIEW
- TERMS - EMBRYOLOGY
(Bie, Contents) V1 JPG
(Chung BRS 2018, Contents) V1 PDF
(Harrell LIR 2018, Contents) V1 PDF
(Harrell LIR 2018, Foundations) V1 PDF
(Dudek HY 2014, Contents) V1 PDF
(Kamina Générale, Introduction)
V1 PDF
(Goldberg MRS Anatomy 2016, Intro terms) V1 PDF
GENERAL ASPECTS
SKELETON
SPINAL COLUMN
NERVOUS
AIRWAYS
DIGESTIVE
COMPARATIVE MORPHOLOGY
POLARIZATION
TOC
SYSTEMS
TOC
MEMBRANES : FASCIA SEROSA MENINGE
(Kamina Anatomie Générale) V1 PDF
TOC
SKELETAL - BONE & CARTILAGE
(Kamina Anatomie Générale) V1 PDF
(Goldberg MRS Anatomy 2016) V1 PDF
TOC
ARTICULAR - JOINTS & LIGAMENTS
(Kamina Anatomie Générale) V1 PDF
(Goldberg MRS Anatomy 2016) V1 PDF
TOC
MUSCULAR
(Kamina Anatomie Générale) V1 PDF
(Goldberg MRS Anatomy 2016) V1 PDF
(Goldberg MRS Anatomy 2016, Bursae & synovial sheaths) V1 PDF
TOC
INTEGUMENTARY - SKIN
(Kamina Anatomie Générale)
V1 PDF
TOC
CIRCULATORY : HEART, ARTERIES, VEINS & LYMPHATICS
(Kamina Anatomie Générale) V1 PDF
(Chung BRS 2018) V1 PDF
TOC
HEART
(Goldberg MRS Anatomy 2016) V1 PDF
TOC
ARTERIES
(Goldberg MRS Anatomy 2016) V1 PDF
CORONARY
ASCENDING & ARCH OF AORTA
INTERNAL CAROTID, VERTEBROBASILAR SYSTEM & CIRCLE OF WILLIS
OPHTHALMIC
EXTERNAL CAROTID
MAXILLARY
MIDDLE MENINGEAL
SUBCLAVIAN
AXILLARY
BRACHIAL
RADIAL
ULNAR
THORACIC (DESCENDING) AORTA
ABDOMINAL AORTA
EXTERNAL ILIAC
COELIAC TRUNK
SUPERIOR MESENTERIC
INFERIOR MESENTERIC
INTERNAL ILIAC
FEMORAL
POPLITEAL
ANTERIOR TIBIAL
POSTERIOR TIBIAL
FIBULAR (PERONEAL)
ANASTOMOSES AROUND SCAPULA
ANASTOMOSES AROUND HIP
TOC
VEINS
(Goldberg MRS Anatomy 2016) V1 PDF
INTRACRANIAL SINUSES & VV
INTERNAL & EXTERNAL JUGULAR
SUPERIOR CAVA
AZYGOS
INFERIOR CAVA
PORTAL
TOC
LYMPHATICS
(Dudek HY 2014, Harrell LIR 2018, Goldberg MRS 2016, Whitaker 2016) V1 PDF
Deep lymphatics follow arteries &
supericial ones follow veins
THORACIC & RIGHT LYMPHATIC DUCTS
LYMPH NODES
HEAD & NECK
THORAX
ABDOMEN
UPPER LIMB
LOWER LIMB
TOC
VISCERAL
(Kamina Anatomie Générale)
V1 PDF
TOC
DIGESTIVE
Retroperitoneal structures
Important gastrointestinal ligaments
Falciform ligament
Hepatoduodenal ligament
Hepatogastric ligament
Gastrocolic ligament
Gastrosplenic ligament
Splenorenal ligament
Digestive tract anatomy
Digestive tract histology
Abdominal aorta and branches
Gastrointestinal blood supply and innervation
Celiac trunk
Portosystemic anastomoses
Pectinate line
Liver tissue architecture
Biliary structures
Femoral region
Femoral triangle
Femoral sheath
Inguinal canal
Myopectineal orifice
Hernias
Diaphragmatic hernia
Indirect inguinal hernia
Direct inguinal hernia
Femoral hernia
TOC
RESPIRATORY
(Le FA 1 2021) V1 PDF
TOC
GENITO-URINARY
TOC
URINARY
TOC
REPRODUCTIVE
TOC
ENDOCRINE
TOC
REGIONS
TOC
LIMBS
LIMBS - DEVELOPMENT
TOC
UPPER LIMB
(Kamina Membre Supérieur et Dvpt des Membres)
V1 PDF
(Harrell LIR 2018) V1 PDF
BONES OF THE UPPER LIMB
JOINTS & LIGAMENTS OF THE UPPER LIMB
MUSCLES OF THE UPPER LIMB
Rotator cuff muscles
Arm abduction
Wrist region
Hand muscles
Distortions of the hand
VESSELS OF THE UPPER LIMB
ARTERIAL SUPPLY
VENOUS DRAINAGE
TOC
NERVES OF THE UPPER LIMB
(Kamina, Sommaire) V1 PDF
Axillary (C5-C6)
Musculocutaneous (C5-C7)
Radial (C5-T1)
Median (C5-T1)
Ulnar (C8-T1)
Recurrent branch of median nerve (C5-T1)
Brachial plexus lesions
Erb palsy (“waiter’s tip”)
Klumpke palsy
Thoracic outlet syndrome
Winged scapula
CUTANEOUS NERVES OF THE UPPER LIMB
BRACHIAL PLEXUS
NERVE LESIONS
REGIONS OF THE UPPER LIMB
SHOULDER REGION
ELBOW REGION
WRIST AND HAND REGION
CROSS SECTIONAL ANATOMY OF RIGHT ARM AND RIGHT FOREARM
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VEINS & PULSES
SHOULDER, SURFACE MARKINGS
AXILLA
SHOULDER SPACES, QUADRANGULAR,
MEDIAL & LATERAL TRIANGULAR
CUBITAL FOSSA
PRONATOR TERES
WRIST, VENTRAL ASPECT
HAND, ANATOMICAL SNUFFBOX
HAND, AUTONOMOUS SENSORY AREAS
HAND, FLEXOR RETINACULUM & CARPAL
TUNNEL
HAND, PALMAR ARTERIAL ARCHES
BONES OF HAND
UPPER LIMB MYOTOMES
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TOC
LOWER LIMB
(Kamina Membre inférieur)
V1 PDF
(Harrell LIR 2018) V1 PDF
BONES OF THE LOWER LIMB
JOINTS & LIGAMENTS OF THE LOWER LIMB
Knee exam
Anterior drawer sign
Posterior drawer sign
Abnormal passive abduction
Abnormal passive adduction
McMurray test
Ankle sprains
MUSCLES OF THE LOWER LIMB
Actions of hip muscles
Abductors
Adductors
Extensors
Flexors
Internal rotation
External rotation
VESSELS OF THE LOWER LIMB
ARTERIAL SUPPLY
VENOUS DRAINAGE
TOC
NERVES OF THE LOWER LIMB
(Kamina, Sommaire) V1 PDF
Iliohypogastric (T12-L1)
Genitofemoral nerve (L1-L2)
Lateral femoral cutaneous (L2-L3)
Obturator (L2-L4)
Femoral (L2-L4)
Sciatic (L4-S3)
Common (fibular) peroneal (L4-S2)
Tibial (L4-S3)
Superior gluteal (L4-S1)
Inferior gluteal (L5-S2)
Pudendal (S2-S4)
Signs of lumbosacral radiculopathy
Neurovascular pairing
CUTANEOUS NERVES OF THE LOWER LIMB
THE LUMBAR PLEXUS
NERVE LESIONS
REGIONS OF THE LOWER LIMB
HIP AND GLUTEAL REGION
KNEE REGION
ANKLE AND FOOT REGION
CROSS-SECTIONAL ANATOMY OF RIGHT THIGH AND RIGHT LEG
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VEINS & PULSES
GLUTEAL REGION (SCIATIC FORAMINA AND OBTURATOR CANAL)
THIGH, FEMORAL TRIANGLE & SAPHENOUS OPENING
THIGH, FEMORAL ARTERY & MERALGIA
PARAESTHETICA
THIGH, ADDUCTOR (SUBSARTORIAL) CANAL
POPLITEAL REGION
ANKLE, TENDONS & NEUROVASCULAR
RELATIONS
BONES OF FOOT
ACCESSORY OSSIICATION
ARCHES OF FOOT
LOWER LIMB MYOTOMES
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TOC
HEAD NECK BACK
(Kamina Tete Cou Dos - Nerfs Cervicaux Dorsaux, Plexus Cervical et Tronc Sympathique - Organes Vision Vestibulo-Cochléaire Olfaction - )
V1 PDF
(Harrell LIR 2018 Head & CN) V1 PDF
(Harrell LIR 2018 Neck) V1 PDF
(Harrell LIR 2018 Back) V1 PDF
TOC
HEAD
CRANIAL BONE - SCALP
BRAIN
FACE
TEMPORAL REGION
PTERYGOPALATINE FOSSA
ORAL REGION
NOSE & EAR
ORBIT
PARASYMPATHETIC GANGLIA IN THE HEAD
SKULL
SCALP
MENINGES
MUSCLES OF THE HEAD
ARTERIAL SUPPLY
VENOUS DRAINAGE
CLINICAL CONSIDERATIONS
CRANIAL NERVES
TOC
NECK
NECK
ENDOCRINE ORGANS IN THE NECK
RESPIRATORY STRUCTURES IN THE NECK
ALIMENTARY STRUCTURES IN THE NECK
MUSCLES OF THE NECK
CERVICAL PLEXUS
CERVICAL TRIANGLES OF THE NECK
LARYNX
THYROID GLAND
PARATHYROID GLAND
PAROTID GLAND
CROSS SECTION OF THE NECK AT THE LEVEL OF C7 VERTEBRA
TOC
CRANIUM
CRANIUM IN GENERAL
DEVELOPMENT OF CRANIUM
BONES OF THE CRANIUM
BONES OF THE FACE
CAVITIES & FORAMINA
TOC
MANDUCATORY APPARATUS
TEMPOROMANDIBULAR JOINT
MUSCLES OF MASTICATION
TEETH
TOC
BACK
BACK IN GENERAL
VERTEBRAL COLUMN
NORMAL & ABNORMAL CURVATURES OF THE VERTEBRAL COLUMN
VERTEBRAL LEVELS OF VARIOUS ANATOMICAL STRUCTURES
JOINTS
VASCULATURE OF THE VERTEBRAL COLUMN
CLINICAL CONSIDERATIONS
NORMAL RADIOLOGY
MUSCLES OF THE BACK
SPINAL CORD
TOC
HEAD & NECK
HEAD & NECK : TOPOGRAPHY & MUSCLES
SUPERFICIAL TOPOGRAPHY OF THE HEAD & NECK
MUSCLES OF THE HEAD
MUSCLES & ANTERIOR SPACES OF THE NECK
HEAD & NECK : VESSELS & NERVES
ARTERIES OF THE HEAD & NECK
VEINS OF THE HEAD & NECK
LYMPHATICS OF THE HEAD & NECK
TOC
CERVICAL SPINAL NERVES - CERVICAL SYMPATHETIC TRUNK
HEAD & NECK : VISCERA
DEVELOPMENT OF THE BRANCHIAL APPARATUS
MOUTH - ORGAN OF TASTE
SALIVARY GLANDS
PHARYNX
LARYNX
THYROID & PARATHYROID GLANDS
THYMUS
TOC
SENSORY ORGANS
(Kamina Anatomie Générale)
V1 PDF
TOC
EYE
(Goldberg MRS Anatomy 2016) V1 PDF
BONY ORBIT
EYELIDS AND LACRIMAL APPARATUS
THE GLOBE OR EYEBALL
EXTRAOCULAR MUSCULATURE
ARTERIAL SUPPLY OF THE ORBIT
VENOUS DRAINAGE OF THE ORBIT
CLINICAL CONSIDERATIONS
TOC
EAR
(Goldberg MRS Anatomy 2016) V1 PDF
GENERAL FEATURES
EXTERNAL EAR
MIDDLE EAR
INNER EAR
CLINICAL CONSIDERATIONS
TOC
NOSE
MOUTH
SKIN
TOC
THORAX & ABDOMEN
(Kamina Thorax & Abdomen - SNA Thoraco-Abdominal - )
V1 PDF
TOC
THORAX
(Harrell LIR 2018 Thorax) V1 PDF
xxx
THORACIC WALL
MEDIASTINUM, PLEURA & ORGANS OF RESPIRATION
PERICARDIUM & HEART
STRUCTURES IN THE POSTERIOR MEDIASTINUM
xxx
xxx
VEINS, UPPER MEDIASTINUM & LOWER NECK
PLEURAL RELECTIONS & LUNG MARKINGS
HEART, VALVES & AUSCULTATION SITES
THE BREAST
xxx
TOC
ABDOMEN
(Harrell LIR 2018 Abdomen) V1 PDF
ANTERIOR WALL, REGIONS
LAYERS
INGUINAL CANAL
RETROPERITONEUM
THE PECTINATE LINE
ANTERIOR WALL, SURFACE MARKINGS
DEEP INGUINAL RING & INGUINAL
POSTERIOR ASPECT & BACK
INGUINAL LIGAMENT & CANAL
EXPLODED INGUINAL CANAL
BOUNDARIES OF THE INGUINAL CANAL
TRIANGLE
FEMORAL CANAL, SHEATH & RING
TRANSPYLORIC PLANE
ARTERIAL SUPPLY OF THE
GASTRO-INTESTINAL TRACT
BRANCHES OF THE INTERNAL
ILIAC ARTERY
AXIAL SECTION ACROSS FAR LEFT SIDE
OF LESSER SAC
LESSER SAC & LESSER OMENTUM
EPIPLOIC FORAMEN
PERINEUM, MALE
PERINEAL POUCHES, DEEP & SUPERICIAL
TOC
PERINEUM & PELVIS
(Harrell LIR 2018 Perineum & Pelvis) V1 PDF
(Kamina Organes Urinaires & Génitaux - Nerfs Pelviens et Perineaux - )
V1 PDF
TOC
NEUROANATOMY
TOC
OVERVIEW OF THE NERVOUS SYSTEM - GROSS STRUCTURE OF THE BRAIN
(Kamina, Neuroanatomie Générale) V1 PDF
(Kamina, Organisation SNC SNP Imagerie) V1 PDF
INTRODUCTION
ORIENTATION
CNS = BRAIN + SC
SC = Ascending tracts + Descending tracts + Interneurons
DIVISIONS OF THE BRAIN = ENCEPHALON
BRAINSTEM
CEREBELLUM
DIENCEPHALON
HYPOPHYSIS
CEREBRUM
TELENCEPHALON = CEREBRUM
CEREBRAL HEMISPHERES
Frontal lobe
Parietal lobe
Temporal lobe
Occipital lobe
Insular lobe
Limbic lobe
Olfactory structures
BASAL NUCLEI (GANGLIA)
LATERAL VENTRICLES
CEREBRAL CORTEX
WHITE MATTER
FIBER PATHWAYS ASSOCIATED WITH THE CEREBRUM
INTERNAL CAPSULE
SUPERIOR LONGITUDINAL FASCICULUS
INFERIOR LONGITUDINAL FASCICULUS
CORPUS CALLOSUM
ANTERIOR COMMISSURE
UNCINATE FASCICULUS
CINGULUM
BASAL NUCLEI
CAUDATE
PUTAMEN
GLOBUS PALLIDUS
SUBTHALAMIC NUCLEUS
FIBER PATHWAYS ASSOCIATED WITH THE BASAL NUCLEI
ANSA LENTICULARIS
LENTICULAR FASCICULUS
THALAMIC FASCICULUS
NIGROSTRIATAL PATHWAY
STRIATONIGRAL PATHWAY
DIENCEPHALON
EPITHALAMUS
(DORSAL) THALAMUS
HYPOTHALAMUS
SUBTHALAMUS (VENTRAL THALAMUS)
THIRD VENTRICLE AND ASSOCIATED STRUCTURES
BRAINSTEM
MESENCEPHAION
Anterior surface
Posterior surface
PONS
Anterior surface
Posterior surface
MEDULLA OBLONGATA
Anterior surface
Posterior surface
CEREBELLUM
Hemispheres
Vermis
Flocculus and vermal nodulus
Tonsil
Superior cerebellar peduncle
Middle cerebellar peduncle
Inferior cerebellar peduncle
Anterior lobe
Posterior lobe
FIocculonoduIar lobe
IMAGING ATLAS OF THE BRAIN & BRAINSTEM
PERIPHERAL NERVOUS SYSTEM
PERIPHERAL RECEPTORS
NERVE FIBERS
PERIPHERAL NERVES
SPINAL CORD
TOC
NEURO-EMBRYOLOGY - DEVELOPMENT
(Kamina Neurogenèse)
V1 PDF
(Kamina Nerfs Spinaux)
V1 PDF
(Kamina Nerfs Craniens) V1 PDF
(Kamina Autonome) V1 PDF
(Kamina Encéphale) V1 PDF
OVERVIEW
18 20 22
DEVELOPMENT OF THE NEURAL TUBE
CLINICAL SIGNIFICANCE
NEURAL CREST
CLINICAL SIGNIFICANCE
PLACODES
STAGES OF NEURAL TUBE DEVELOPMENT
PROSENCEPHALON (FOREBRAIN)
MESENCEPHALON (MIDBRAIN)
CEPHALIC FLEXURE
RHOMBENCEPHALON (HINDBRAIN)
CERVICAL FLEXURE
DEVELOPING SPINAL CORD
CLINICAL SIGNIFICANCE
NEURAL TUBE WALL
SPINAL CORD (MEDULLA SPINALIS)
CLINICAL SIGNIFICANCE
MEDULLA OBLONGATA (MYELENCEPHALON)
METENCEPHALON
MESENCEPHALON (MIDBRAIN)
DEVELOPMENT OF THE DIENCEPHALON, OPTIC STRUCTURES, AND HYPOPHYSIS
DEVELOPMENT OF THE TELENCEPHALON
CONGENITAL MALFORMATIONS OF THE CNS
TOC
NEURO-HISTOLOGY
(Kamina) V2 PDF
OVERVIEW
NEURONS
NEUROGLIA
NEURON
ASTROCYTE
MICROGLIA
OLIGODENDROCYTE
EPENDYMAL
SCHWANN
PARTS OF A NEURON
CLINICAL SIGNIFICANCE
NERVE CELL DEGENERATION AND REGENERATION
AXONAL TRANSPORT
CAPILLARIES OF THE CNS
SENSORY RECEPTORS
PAIN & TEMPERATURE
FNE
A-δ C (unmyelinated) - ALS - SA
CUTANEOUS MECHANORECEPTORS
MERKEL
Crude touch - A-β or type II - Slow - ALS & PCMLS
PACINIAN
Pressure and vibration - Very fast - PCMLS
MEISSNER
Fine touch - A-β or type II - Fast - PCMLS
RUFFINI
Tension and stretch
MUSCLE & TENDON R
MUSCLE SPINDLE
Muscle stretch - A-α or type Ia A-β or type II - Slow
GOLGI TENDON ORGAN
Muscle tension - A-α or type Ib
TOC
MENINGES, VENTRICLES & CSF
(Kamina Générale Méninges Ventricules & LCR) V1 PDF
(Kamina Ventricules Encéphaliques) V1 PDF
(Kamina Méninges & LCR) V1 PDF
MENINGES & SPACES AROUND THE BRAIN
DURA MATER
SUBDURAL SPACE
ARACHNOID MATER
SUBARACHNOID SPACE
PIA MATER
BRAIN
CLINICAL SIGNIFICANCE
MENINGEAL SPACES
MENINGIOMAS
DURAL FOLDS AND SINUSES
FALX CEREBRI: Found in the longitudinal fissure
TENTORIUM CEREBELLI: Found between the occipital lobes and the cerebellum; divides cranial vault into supra- and infratentorial compartments
FALX CEREBELLI: Found between the cerebellar hemispheres
DIAPHRAGMA SELLA: Circular diaphragm over the sellae turcica to protect the hypophysis; contains aperture for passage of hypophyseal stalk
CLINICAL SIGNIFICANCE
MENINGES & SPACES AROUND THE SPINAL CORD
EPI-DURAL SPACE
DURA MATER
SUB-DURAL SPACE
ARACHNOID MATER
SUBARACHNOID SPACE
PIA MATER
SPINAL CORD
CLINICAL SIGNIFICANCE
VENTRICLES & CEREBROSPINAL FLUID
VENTRICLES (PRESENTED IN AN ORDER REPRESENTING THE FLOW OF CSF)
LATERAL VENTRICLES 2
INTERVENTRICULAR FORAMINA (TWO; OF MONRO)
THIRD VENTRICLE
CEREBRAL AQUEDUCT (OF SYLVIUS)
FOURTH VENTRICLE
LATERAL FORAMINA (TWO; OF LUSCHKA) AND MEDIAL FORAMEN (OF MAGENDIE)
SUBARACHNOID SPACE
CLINICAL SIGNIFICANCE
CEREBROSPINAL FLUID
HYDROCEPHALUS
MENINGITIS
HERNIATION
CIRCUMVENTRICULAR ORGANS
area postrema
ORGANUM VASCULOSUM OF THE LAMINA TERMINALIS
MEDIAN EMINENCE OF THE TUBER CINEREUM
SUBFORNICAL ORGAN
SUBCOMMISSURAL ORGAN
PINEAL BODY
AREA POSTREMA
TOC
BLOOD SUPPLY OF CENTRAL NERVOUS SYSTEM
(Kamina Encephale) V1 PDF
(Kamina MS) V1 PDF
VESSELS OF THE BRAIN
VESSELS OF THE SPINAL CORD
ARTERIES OF THE SPINAL CORD
VENOUS DRAINAGE OF THE SPINAL CORD
ARTERIES OF THE BRAIN
CEREBRAL ARTERIAL CIRCLE (OF WILLIS)
MENINGEAL ARTERIES
VEINS OF THE BRAIN
VENOUS DURAL SINUSES
ANGIOGRAPHY
INTRACRANIAL HEMORRHAGE
TOC
SENSORY SYSTEM
BODY
The chain of
ascending neurons sends axon collaterals to mediate reflexes
& affects other ascending & descending systems, an important concept
for pain modulation
TYPES OF SOMATOSENSATION
Pain and temperature
Touch: Fine and crude
Vibratory sense
Proprioception : Conscious and unconscious (reflex)
THREE-NEURON CHAIN (with some exceptions)
First order
Spinal ganglia or sensory ganglia of the head
Conveys sensation from periphery to the CNS
Second order
Within the central nervous system (CNS); spinal cord gray matter or brainstem
Typically gives rise to fibers that cross the midline to reach thalamus
Third order
Within the thalamus
Conveys sensation from the thalamus to the cerebral cortex
DORSAL (POSTERIOR) COLUMN–MEDIAL LEMNISCUS
1°:
Pacinian corpuscle/Meissner's corpuscle → Posterior column (Gracile
fasciculus/Cuneate fasciculus) → Gracile nucleus/Cuneate nucleus
2°: → sensory
decussation/arcuate fibers (Posterior external arcuate fibers, Internal
arcuate fibers) → Medial lemniscus/Trigeminal lemniscus → Thalamus
(VPL, VPM)
3°: → Posterior limb of internal capsule → Postcentral gyrus
ANTEROLATERAL / PAIN
Temperature - Crude Touch - Touch = Tch
Pain & Temperature / lateral spino-thalamic
Crude Touch/ anterior spino-thalamic
Pain, Temperature & Touch/ spino-reticular
Pain / spino-hypothalamic
Pain, Temperature & Touch / spino-tectal
Pain / spino-mesencephalic
Fast/lateral
1° (Free nerve ending → A delta fiber) → 2° (Anterior white commissure → Lateral P+T & Anterior CTch Spino-thalamic tract → Spinal lemniscus → VPL of Thalamus) → 3° (Postcentral gyrus) → 4° (Posterior parietal cortex)
2° (Spino-mesencephalic P tract → Superior colliculus of Midbrain tectum)
Slow/medial
1° (Group C nerve fiber → Spino-reticular P+T+Tch tract → Reticular formation) → 2° (MD of Thalamus) → 3° (Cingulate cortex)
CEREBELLAR TRACTS
Anterior spino-cerebellar
Posterior spino-cerebellar
Cuneo-cerebellar
BIDIRECTIONAL : SPINOCEREBELLAR
Unconscious proprioception
lower limb → 1° (muscle spindles → DRG) → 2° (Posterior thoracic nucleus → Dorsal/posterior spinocerebellar tract → ICP → Cerebellar vermis)
upper limb → 1° (muscle spindles → DRG) → 2° (Accessory cuneate nucleus → Cuneo-cerebellar tract → ICP → Anterior lobe of cerebellum)
Reflex arc
lower limb → 1° (Golgi tendon organ) → 2° (Ventral/anterior spinocerebellar tract→ SCP → Cerebellar vermis)
upper limb → 1° (Golgi tendon organ) → 2° (Rostral spinocerebellar tract → ICP → Cerebellum)
CEREBELLAR AFFERENT
Vestibular nuclei → Vestibulo-cerebellar tract → ICP → Cerebellum → Granule cell
Pontine nuclei → Ponto-cerebellar fibers → MCP → Deep cerebellar nuclei → Granule cell
Inferior olivary nucleus → Olivo-cerebellar tract → ICP → Hemisphere → Purkinje cell → Deep cerebellar nuclei
CEREBELLAR EFFERENT
Dentate nucleus in Lateral hemisphere/ponto-cerebellum → SCP → Dentato-thalamic tract → Thalamus (VL) → Motor cortex
Interposed nucleus in Intermediate hemisphere/spino-cerebellum → SCP → Reticular formation, or → Cerebello-thalamic tract → Red nucleus → Thalamus (VL) → Motor cortex
Fastigial nucleus in Flocculonodular lobe/vestibulo-cerebellum → Vestibulo-cerebellar tract → Vestibular nuclei
HEAD - TRIGEMINAL SENSORY SYSTEM
Pain and temperature and touch / spinal trigeminal tract and nucleus
Fine touch, conscious proprioception and vibratory sense/trigeminal ganglion
Unconscious proprioception / mesencephalic tract and nucleus
TOC
MOTOR SYSTEM
Lateral pathways
Motor cortex → Cortico-spinal tract → Spinal Cord
Motor cortex → Red Nucleus → SC
Anteromedial pathways
Motor cortex → Reticular Nuclei → SC
Motor cortex → Superior Colliculus & Vestibular nuclei→ SC
PYRAMIDAL
voluntary motor system is composed of WM tracts descending from the brain to the periphery - It typically involves a two-neuron chain :
an upper motor neuron (UMN) that is located in the central nervous system (CNS) and
a lower motor neuron (LMN) that stimulates effectors in the periphery
Flexion : Primary motor cortex → Posterior limb of internal capsule → Decussation of pyramids → Corticospinal tract (Lateral Distal body , Anterior Axial body) → Neuromuscular junction
(Flexion : Primary motor cortex → Genu of internal capsule → Cortico-bulbar-nuclear tract → Facial motor nucleus → Facial muscles - Head & face)
EXTRAPYRAMIDAL : INVOLUNTARY
Flexion : Primary motor cortex → Genu of internal capsule → Cortico-bulbar (nuclear) tract → Facial motor nucleus → Facial muscles - Head & face
Flexion : Red nucleus → Rubrospinal tract
Extension : Vestibulocerebellum → Vestibular nuclei → Vestibulospinal tract - Medial and lateral
Extension : Vestibulocerebellum → Reticular formation → Reticulospinal tract - Pontine and medullary
Midbrain tectum → Tectospinal tract → muscles of neck
EXTRAPYRAMIDAL : BASAL NUCLEI
Prefrontal cortex → Basal ganglia → Thalamus → Motor cortex Area 6
Direct : 1°
(Motor cortex → Striatum) → 2° (GPi) → 3° (Lenticular fasciculus/Ansa
lenticularis → Thalamic fasciculus → VL of Thalamus) → 4°
(Thalamocortical radiations → Supplementary motor area) → 5° (Motor
cortex)
Indirect :
1° (Motor cortex → Striatum) → 2° (GPe) → 3° (Subthalamic fasciculus →
Subthalamic nucleus) → 4° (Subthalamic fasciculus → GPi) → 5°
(Lenticular fasciculus/Ansa lenticularis → Thalamic fasciculus → VL of
Thalamus) → 6° (Thalamocortical radiations → Supplementary motor area)
→ 7° (Motor cortex)
Nigrostriatal pathway : Pars compacta → Striatum
CEREBELLUM
Sensory cortex → Pons, cerebellum → Thalamus → Motor cortex Area 4
BIDIRECTIONAL : SPINOCEREBELLAR - SENSORY
Unconscious proprioception
lower limb → 1° (muscle spindles → DRG) → 2° (Posterior thoracic nucleus → Dorsal/posterior spinocerebellar tract → ICP → Cerebellar vermis)
upper limb → 1° (muscle spindles → DRG) → 2° (Accessory cuneate nucleus → Cuneo-cerebellar tract → ICP → Anterior lobe of cerebellum)
Reflex arc
lower limb → 1° (Golgi tendon organ) → 2° (Ventral/anterior spinocerebellar tract→ SCP → Cerebellar vermis)
upper limb → 1° (Golgi tendon organ) → 2° (Rostral spinocerebellar tract → ICP → Cerebellum)
CEREBELLAR AFFERENT
Vestibular nuclei → Vestibulo-cerebellar tract → ICP → Cerebellum → Granule cell
Pontine nuclei → Ponto-cerebellar fibers → MCP → Deep cerebellar nuclei → Granule cell
Inferior olivary nucleus → Olivo-cerebellar tract → ICP → Hemisphere → Purkinje cell → Deep cerebellar nuclei
CEREBELLAR EFFERENT
Dentate nucleus in Lateral hemisphere/ponto-cerebellum → SCP → Dentato-thalamic tract → Thalamus (VL) → Motor cortex
Interposed nucleus in Intermediate hemisphere/spino-cerebellum → SCP → Reticular formation, or → Cerebello-thalamic tract → Red nucleus → Thalamus (VL) → Motor cortex
Fastigial nucleus in Flocculonodular lobe/vestibulo-cerebellum → Vestibulo-cerebellar tract → Vestibular nuclei
TOC
SPINAL CORD
(Kamina)
V2 PDF
TOC
MORPHOLOGY OF THE SPINAL CORD
INTRODUCTION
meninges
EXTERNAL MORPHOLOGY
LOCATION
medulla oblongata
subarachnoid space
ATTACHMENTS
pia mater
Denticulate ligaments
Filum terminale
Spinal nerve roots
SHAPE
cervical lumbar enlargements
conus medullaris
SPINAL NERVES
8 cervical, 12 thoracic, 5 lumbar, 5 sacral,1 coccygeal
Functional components of spinal nerve fibers
General somatic afferent (GSA) fibers
General visceral afferent (GVA) fibers
General somatic efferent (GSE) fibers
General visceral efferent (GVE) fibers
Components and branches of spinal nerves
Posterior root
Spinal ganglion - intervertebral foramen - pseudounipolar neurons
Anterior root
Cauda equina
Spinal nerve rami
SPINAL NERVE RAMI
Posterior ramus
innervates the skin and muscles of the back
Anterior ramus
innervates the anterior and lateral muscles and skin of the trunk, extremities,and visceral organs
Meningeal ramus
innervates the meninges and vertebral column
Gray communicating rami
contain UNmyelinated POSTganglionic sympathetic fibers
associated with ALL spinal nerves
White communicating rami
contain myelinated PREganglionic sympathetic fibers AND myelinated GVA fibers (splanchnic nerves)
found only in thoracolumbar segments of the spinal cord (Tl—L2)
SPINAL NERVE INNERVATION
somite
Dermatome
Myotome
Sclerotome
SURFACE STRUCTURE & SULCI
Anterior median fissure
Anterior lateral sulcus
Posterior lateral sulcus
Posterior intermediate sulcus
Posterior median sulcus
INTERNAL MORPHOLOGY
H-shaped
Rexed laminae
GRAY MATTER
POSTERIOR HORN (COLUMN)
Posteromarginal nucleus (Rexed lamina I)
associated with light touch, pain, and temperature sensation
origin of some fibers of anterolateral system
Substantia gelatinosa (Rexed lamina ll)
homologous to the spinal trigeminal nucleus
associated with light touch, pain, and temperature sensation
origin of some fibers of anterolateral system
Nucleus proprius (Rexed laminae Ill and IV)
associated with light touch, pain, and temperature sensation
origin of some fibers of anterolateral system
Posterior thoracic nucleus (also known as nucleus dorsalis of Clarke) (Rexed lamina VII)
found at the base of the posterior horn
extends from (C8) T1 to L2
homologous to the accessory cuneate nucleus of the medulla
subserves unconscious proprioception from muscle spindles and Golgi tendon organs (GTOs)
the origin of the posterior spinocerebellar tract
LATERAL HORN (COLUMN) (REXED LAMINA VII)
receives viscerosensory input
found between the posterior and the anterior horns
extends from T1 to L2
contains the intermediolateral nucleus (column), a visceromotor nucleus that extends from T1 to L2
contains preganglionic sympathetic neurons (GVE)
contains, at T1—T2, the ciliospinal center of Budge (sympathetic innervation of the eye)
ANTERIOR HORN (COLUMN) (REXED LAMINAE VII, VIII, AND IX)
predominantly motor nuclei
Spinal border cells
extend from L2 to S3
subserve unconscious proprioception from GTOs and muscle spindles
the origin of the anterior spinocerebellar tract
Sacral parasympathetic nucleus (Rexed lamina VII)
extends from S2 to S4
gives rise to preganglionic parasympathetic fibers that innervate the pelvic viscera via the pelvic splanchnic nerves
Somatic motor nuclei (Rexed lamina IX)
subdivided into medial and lateral groups that innervate axial and appendicular muscles, respectively
Spinal accessory nucleus (Rexed lamina IX)
extends from C1 to C6
gives rise to the spinal accessory nerve (CN XI)
innervates the sternocleidomastoid and trapezius
Phrenic nucleus (Rexed lamina IX)
extends from C3 to C5
innervates the diaphragm
WHITE MATTER
POSTERIOR FUNICULUS (POSTERIOR COLUMN)
located between the posterior median sulcus and the posterior lateral sulcus
is subdivided above T6 into two fasciculi
Fasciculus gracilis
Fasciculus cuneatus
found only at the upper thoracic and cervical cord levels (Cl—T6)
LATERAL FUNICULUS
ANTERIOR FUNICULUS
located between the anterior median fissure and the anterior lateral sulcus
contains the anterior white commissure
located between the central canal and the anterior medial fissure
contains decussating spinothalamic fibers
CHARACTERIZATION OF SPINAL CORD LEVELS
Cervical cord
Thoracic cord
Lumbar cord
Sacral cord
Coccygeal segment
MYOTATIC REFLEX
Afferent limb
Efferent limb
TOC
TRACTS OF THE SPINAL CORD
TOC
ASCENDING TRACTS OF THE SPINAL CORD - SENSORY- BODY - (HEAD = TRIGEMINAL SENSORY SYSTEM)
POSTERIOR COLUMN(S) - MEDIAL LEMNISCUS PATHWAY
Convey information on fine touch, conscious proprioception, and vibratory sense
Pacinian and Meissner’s corpuscles, joint receptors, muscle spindles, and Golgi tendon organs (GTOs)
First-order neurons
fasciculus gracilis
fasciculus cuneatus
Second-order neurons
internal arcuate fibers - medial lemniscus - VPL
Third-order neurons
somatosensory cortex
Unlike other
sensory systems, the posterior column pathways do not send axon
collaterals to the brainstem reticular formation as they project
cranially
The information ascending regarding fine touch does not reflexively
initiate a pain control mechanism, nor do they need to “activate” the
cortex
ANTEROLATERAL SYSTEM
The
anterolateral system (tract) not only contains the anterior and lateral
spinothalamic tracts but also includes spinomesencephalic,
spinoreticular, and spinolimbic fibers
Pain,
temperature, and crude touch all ascend the spinal cord as part of the
anterolateral system located in the anterior aspect of the lateral
funiculus and lateral aspect of the anterior funiculus
PAIN & TEMPERATURE / LATERAL SPINO-THALAMIC
Mediate pain, temperature, and itch
Somatotopically organized
Important in the localization of stimuli
Reach consciousness
First-order neurons
FNE - posterolateral tract (of Lissauer) - synapse on second-order neurons in posterior horn of spinal cord, including the substantia gelatinosa and nucleus proprius
Second-order neurons
anterior white commissure - send axon collaterals to brainstem reticular formation
Third-order neurons
VPL neurons
- project via the posterior limb of the internal capsule to the
somatesthetic cortex of the postcentral gyrus (areas 3, 1, and 2)
Intralaminar neurons - project to the caudatoputamen and to the frontal and parietal cortex
CRUDE TOUCH / ANTERIOR SPINO-THALAMIC
Mediate light touch
Reach consciousness
First-order neurons
free nerve endings and on Merkel disks
Second-order neurons
posterior horn - send axon collaterals to brainstem reticular formation
Third-order neurons
VPL nucleus
PAIN, TEMPERATURE & TOUCH / SPINO-RETICULAR
Involved in adjusting the level of attention to incoming sensation
Cell bodies within the CNS are found in the intermediate gray and anterior and posterior horns
Project to multiple synaptic contacts within the brainstem reticular formation
Much of the tract is composed axon collaterals from spinothalamic fibers
PAIN / SPINO-HYPOTHALAMIC
Influence the autonomic response to incoming pain
Cell bodies within the CNS are found in the intermediate gray and anterior and posterior horns
Project to widespread hypothalamic nuclei
PAIN, TEMPERATURE & TOUCH / SPINO-TECTAL
Influence reflexive head movement
Fibers that are part of the anterolateral system terminate in the superior and inferior colliculi
PAIN / SPINO-MESENCEPHALIC
Influence descending pain control mechanisms
Fibers arise from cells in the posterior horn and ascend as part of the anterolateral system
DESCENDING PAIN CONTROL MECHANISMS
are composed of various descending pathways that serve to inhibit ascending pain information
The most commonly accepted theory is the gate control theory of pain
The theory
indicates that at each point in the ascending pain pathway, it is
possible for a descending fiber to inhibit the ascending pain signal
(i.e., act as a “gate” for the transmission)
Such points include local inhibition in the spinal cord, brainstem reticular formation, and thalamus
The primary
sensory cortex has a somatotopic organization, which is represented by
the homunculus: a representation of the body superimposed on the
primary sensory cortex that indicates disproportionate representation
of some body parts over others (e.g., the hand versus the back)
CEREBELLAR TRACTS FOR THE BODY
Information enters the cerebellum from the spinal cord and brainstem, which the cerebellum uses to coordinate movements
The information includes touch, pressure, and unconscious proprioception from muscle spindles and Golgi tendon organs
POSTERIOR SPINO-CEREBELLAR TRACT - LOWER LIMB
Unconscious proprioceptive information for fine coordination and control of individual muscles
Act as afferent limb of stretch reflexes
Posterior spinocerebellar (lower limb) and Cuneocerebellar (upper limb) tracts are homologs
First-order neurons
Peripheral processes of first-order neurons end on Golgi tendon organs and muscle spindles primarily in lower limbs;
central processes enter posterior root to synapse on second-order neurons in the posterior thoracic nucleus
Second-order neurons
Second-order neurons are located in the posterior thoracic nucleus, only found between the C8 and L3 cord levels;
ascending processes ascend in the ipsilateral lateral funiculus as the posterior spinocerebellar tract and enter the cerebellum via the inferior cerebellar peduncle
Fibers ascend to cerebellar cortex as mossy fibers
ANTERIOR SPINO-CEREBELLAR TRACT - LOWER EXTREMITY AS A WHOLE
Unconscious proprioceptive information for control of groups of muscles and coordination of the lower limbs
Act as afferent limb of stretch reflexes
First-order neurons
Peripheral processes of first-order neurons end on Golgi tendon organs and muscle spindles;
central processes enter posterior root to synapse on spinal border cells around the anterior horn between L1 and S2 cord levels
Second-order neurons
Second-order
neurons give rise to fibers that decussate in the anterior white
commissure and ascend in the lateral funiculus as the anterior spinocerebellar tract;
fibers decussate (back to the side of origin) as they enter the cerebellum via the superior cerebellar peduncle
Fibers ascend to cerebellar cortex as mossy fibers
CUNEO-CEREBELLAR TRACT - UPPER EXTREMITY EQUIVALENT OF THE POSTERIOR
First-order neurons
Peripheral processes of first-order neurons end on Golgi tendon organs and muscle spindles, primarily in upper limbs;
central processes enter fasciculus cuneatus to ascend to synapse in the medulla on the accessory (lateral) cuneate nucleus
Second-order neurons
Second-order
neurons are located in the accessory cuneate nucleus; give rise to
fibers that enter the ipsilateral cerebellum via the inferior
cerebellar peduncle
HEAD
TRIGEMINAL SENSORY SYSTEM
TOC
DESCENDING TRACTS OF THE SC
LATERAL CORTICOSPINAL (PYRAMIDAL) TRACT / DISTAL BODY - LATERAL PATHWAY
volitional skilled motor activity
paracentral lobule
Description
UMN located in primary motor cortex, precentral gyrus: Brodmann’s area 4; precentral motor cortex (area 4) postcentral sensory cortex (areas 3, 1, and 2)
UMN receives input from association and premotor cortex and motor-related thalamic nuclei
UMN fibers descend via internal capsule
90%
of corticospinal fibers decussate in the pyramidal decussation, the
remaining 10% cross in the spinal cord at the level of the LMN they
innervate
giant cells of Betz
crus cerebri
Fonction
Controls distal musculature
Fibers decussate in the caudal medulla at the pyramidal decussation
Terminate on LMN in anterior horn at all spinal cord levels
Axon collaterals that project to basal nuclei, thalamus, and reticular formation are responsible for motor overlap
Somatotopically organized
ANTERIOR CORTICOSPINAL TRACT / AXIAL BODY - LATERAL PATHWAY
Fonction
Controls axial musculature
Most fibers decussate in the spinal cord (anterior white commissure)
Terminate on LMN in medial intermediate zone at all levels of the spinal cord
(CORTICONUCLEAR ( CORTICOBULBAR) TRACT / HEAD AND FACE)
UMNs descend bilaterally, although the majority of the fibers project to the contralateral LMN target
UMNs synapse in
the brainstem (and cervical cord) on LMN nuclei associated with cranial
nerves (CNs): III, IV, V, VI, VII, IX, X, XI, and XII
Bilateral control
The exception to bilateral control is that innervation of the facial
motor nucleus is contralateral only for the lower aspect of the face;
the upper parts of the nucleus that control the upper aspect of the
face are innervated bilaterally
The
primary motor cortex has a somatotopic organization, which is
represented by the homunculus: a representation of the body
superimposed on the primary motor cortex, which indicates the
disproportionate representation of some body parts over others (e.g.,
the hand versus the back)
RUBRO-SPINAL TRACT - LATERAL PATHWAY
Description
arises in the contralateral red nucleus of the midbrain
anterior to the lateral corticospinal tract
Fonction
plays a role in the control of flexor tone
VESTIBULO-SPINAL : MEDIAL AND LATERAL - ANTEROMEDIAL PATHWAY
Description
UMN in lateral vestibular nucleus of pons and medial vestibular nucleus of medulla
Receive input from mechanoreceptors of inner ear
Lateral vestibulospinal pathway is ipsilateral; medial pathway is bilateral
Both pathways descend anteromedial cord
Fonction
Lateral vestibulospinals synapse on LMN at all cord levels
Medial vestibulospinals travel through medial longitudinal fasciculus to synapse on LMNs in medial aspect of cervical cord
Both pathways are involved in head movement and the maintenance of posture
TECTO-SPINAL
Description
UMN located in midbrain tectum; superior and inferior colliculi
Fibers descend to contralateral anterior funiculus via anteromedial aspect of spinal cord white matter
Terminate on LMNs in cervical spinal cord
Fonction
Transmits impulses for reflexive turning of the head in response to visual and auditory stimuli
Fibers cross midline in tegmental decussation, resulting in primarily contralateral control
RETICULO-SPINAL : PONTINE AND MEDULLARY - ANTEROMEDIAL PATHWAY
Description
UMN in brainstem reticular formation; pons and medulla
Pontine fibers ipsilateral
Medullary fibers bilateral
Fonction
Project to all spinal cord levels
Unconscious control of head, neck, and body
TOC
DESCENDING AUTONOMIC TRACTS OF THE SC
project to sympathetic (Tl—L2) and parasympathetic (S2—S4) centers in the spinal cord
innervate the ciliospinal center (Tl—T2), a pupillary center;
interruption of this hypothalamospinal tract (found in the posterior
quadrant of the lateral funiculus) results in Horner syndrome
TOC
INTEGRATIVE PATHWAYS OF THE SC
ASCENDING PAIN PATHWAYS
pain ascends in all three funiculi.
tracts that carry pain include the lateral spinothalamic and the following :
spinoreticular
spinomesencephalic
spinocervical
postsynaptic fibers in the posterior columns
POSTEROLATERAL TRACT (OF LISSAUER)
(predominantly) white matter tract capping the posterior horn
mainly pain and temperature fibers ascending or descending a few spinal cord segments before synapsing
serves to provide central overlap of pain and temperature
FASCICULUS PROPRIUS
white matter tract surrounding the margins of gray matter at all spinal cord levels
contains fibers ascending or descending multiple levels, which then reenter the gray matter
serves as an intersegmental connection between adjacent cord levels
CLINICAL CORRELATIONS
UMNs
UMN LESIONS
Acute-stage lesions
Flaccid paralysis
Areflexia
Hypotonia
Chronic-stage lesions
Spastic paresis
Hypertonia
Reduction or loss of superficial abdominal and cremasteric reflexes
Extensor toe response (Babinski sign)
Clonus
LMN
LMNs LESIONS
Flaccid paralysis
Areflexia
Muscle atrophy
Fasciculations and fibrillations
TOC
LESIONS OF THE SPINAL CORD
LOWER MOTOR NEURON (LMN) LESIONS
Neurologic deficits resulting from LMNs lesions
Flaccid paralysis
Muscle atrophy (amyotrophy)
Hypotonia
Areflexia
Fasciculations
Fibrillations
Diseases of LMNs
Poliomyelitis
Progressive infantile muscular atrophy (Werdnig—Hoffmann disease)
Kugelberg—Welander disease
UPPER MOTOR NEURON (UMN) LESIONS
pyramidal tract lesions
Lateral Corticospinal Tract lesion
Spastic hemiparesis with muscle weakness
Hyperreflexia (exaggerated MSRs)
Clasp-knife spasticity
Loss of superficial (abdominal and cremasteric) reflexes
Clonus
Babinski sign
Anterior Corticospinal Tract lesion
mild contralateral motor deficit
Hereditary spastic paraplegia or diplegia
SENSORY PATHWAY LESIONS
Posterior column syndrome
tabes dorsalis
ipsilateral sensory deficits :
Loss of tactile discrimination
Loss of position (joint) and vibratory sensation
Stereoanesthesia
Sensory (posterior column) dystaxia
Paresthesias and pain
Hyporeflexia or areflexia
Urinary incontinence, constipation, and impotence
Romberg sign
Lateral spinothalamic tract lesion
Anterior spinothalamic tract lesion
Posterior spinocerebellar lesion
Anterior spinocerebellar lesion
PERIPHERAL NERVOUS SYSTEM LESIONS
Herpes Zoster Shingles
viral infection
T5 to T10
Acute idiopathic polyneuritis
postinfectious polyneuritis
LMN symptoms
(albuminocytologie dissociation)
COMBINED UPPER AND LMN LESIONS
Characteristics
Prototypic type ALS
Lou Gehrig disease
COMBINED MOTOR AND SENSORY LESIONS
Spinal Cord Hemisection (Brown-Séquard Syndrome)
Complete transection of SC
Anterior Spinal Artery Occlusion
Conus medullaris syndrome & Epiconus syndrome
Cauda equina syndrome
Filum terminale tethered cord syndrome
Subacute Combined Degeneration (Vitamin B12 Neuropathy)
Friedreich Ataxia
Syringomyelia
MS
Charcot Marie tooth disease
INTERVERTEBRAL DISK HERNIATION
TOC
SPINAL NERVES
(Kamina)
V1 PDF
(Dudek HY Vertebral Column) V1 PDF
(Dudek HY Spinal Cord & Spinal Nerves) V1 PDF
(Goldberg MRS Anatomy 2016) V1 PDF
CERVICAL PLEXUS (C1,2,3,4,5)
BRACHIAL PLEXUS (C5,6,7,8,T1)
RADIAL (C5,6,7,8,T1)
MUSCULOCUTANEOUS (C5,6,7)
MEDIAN (C6,7,8,T1)
ULNAR (C8,T1)
PHRENIC (C3,4,5)
INTERCOSTAL (TYPICAL)
LUMBAR PLEXUS (T12,L1,2,3,4,5)
FEMORAL (L2,3,4)
OBTURATOR (L2,3,4)
SACRAL PLEXUS (L4,5,S1,2,3,4,5)
SCIATIC (L4,5,S1,2,3)
TIBIAL (L4,5,S1,2,3)
COMMON FIBULAR (PERONEAL) (L4,5,S1,2)
SUPERICIAL FIBULAR (PERONEAL) (L5,S1,2)
DEEP FIBULAR (PERONEAL) (L4,5,S1,2)
LATERAL PLANTAR (S1,2,3)
MEDIAL PLANTAR (L4,5,S1,2,3)
RECEPTORS & EFFECTORS
DERMATOMES &
CUTANEOUS NERVE
DISTRIBUTION
MUSCULAR ACTIVITY
Cervical Plexus (& Cervical Sympathetic Trunk)
(Kamina Nerfs Spinaux Cervicaux) V1 JPG
Phrenic
Intercostal
Upper Limb
(Kamina Nerfs du Membre Supérieur) V1 PDF
Brachial Plexus
Axillary
Radial
Musculocutaneous
Median
Ulnar
Thorax & Abdomen (& Autonomic)
(Kamina Système Nerveux Autonome Thoraco-Abdominal) V1 JPG
Pelvis & Perineum (& Autonomic)
(Kamina Nerfs Pelviens & Perineaux Tome 4) V1 JPG
Lower Limb
(Kamina Nerfs du Membre Inférieur) V1 PDF
Lumbar Plexus
Femoral
Obturator
Sacral Plexus
Sciatic
Tibial
Common fibular
Supericial fibular
Deep fibular (peroneal)
Lateral plantar
Medial plantar
TOC
AUTONOMIC VISCERAL
(Dudek HY) V1 PDF
(Faiz) V1 PDF
(Kamina Neuroanatomy & Dudek HY Anatomy)
V2 PDF
(Goldberg MRS Anatomy 2016) V1 PDF
OVERVIEW
The nervous system can be divided into a somatic and an autonomic nervous system (ANS);
the autonomic or visceral efferent system controls involuntary muscle—smooth and cardiac—and glands throughout the body
Autonomic activity is controlled by the hypothalamus, which is responsible for integrating the ANS and the endocrine system to maintain homeostasis
The ANS is divided into a sympathetic and parasympathetic division
The preganglionic cell body is located in the CNS, and the
postganglionic cell body is located in a peripheral ganglion for both
systems
GVE
controls and regulates smooth muscle, cardiac muscle, and glands
sympathetic - parasympathetic - enteric
preganglionic neurons - postganglionic neurons
general visceral afferent (GVA) fibers run with GVE fibers
all sympathetic fibers in the head are postganglionic and run on branches of CN V to reach their target
Autonomic Output is generally reflexive and is influenced rostrally by the hypothalamus
COMMUNICATING RAMI
GRAY - UNmyelinated - ALL spinal
POSTg sympathetic to SPINAL N & ANS Afferent from SPINAL N then enters white ramus
WHITE - myelinated -T1-L2
Visceral afferents (splanchnic NN) & PREg sympathetic to sympathetic chain
DIVISIONS OF THE AUTONOMIC NERVOUS SYSTEM
SYMPATHETIC DIVISION - THORACOLUMBAR - ADRENERGIC
owing to location of preganglionic cell bodies
VISCEROMOTOR COMPONENT OF THE SYMPATHETIC
CNS → short preganglionic neuron → ganglion → long postganglionic neuron → smooth muscle, cardiac muscle, and glands
PREGANGLIONIC SYMPATHETIC NEURONS - ACETYLCHOLINE
cell bodies located in intermediolateral cell column T1–L2/L3
Fates : Preganglionic axons...
- Enter the paravertebral chain ganglia through white communicating rami, where they synapse with postganglionic neurons at that level
- Travel up or down the paravertebral chain ganglia, where they synapse with postganglionic neurons at upper or lower levels, respectively
- Pass through the paravertebral chain ganglia (i.e., no synapse) as
thoracic splanchnic nerves (greater, lesser, and least),
lumbar splanchnic nerves (L1 to L4), and
sacral splanchnic nerves (L5 and S1 to S3)
which synapse with postganglionic neurons
in prevertebral ganglia (i.e., celiac ganglion, aorticorenal ganglion, superior mesenteric ganglion, inferior mesenteric ganglion) as well as
in the superior hypogastric plexus and inferior hypogastric plexus
- Pass through the paravertebral chain ganglia (i.e., no synapse) as thoracic splanchnic nerves, which synapse with modified postganglionic sympathetic neurons in the adrenal medulla called chromaffin cells
POSTGANGLIONIC SYMPATHETIC NEURONS - NOREPINEPHRINE
paravertebral chain ganglia & prevertebral ganglia
α1-, α2-, β1-, β2-, and β3-adrenergic receptors - smooth muscle, nodal tissue/cardiac muscle, and glands
Fates : Postganglionic axons...
- Leave the paravertebral chain ganglia through gray communicating rami and join all 31 pairs of spinal nerves to innervate
smooth muscle of blood vessels, arrector pili smooth muscle of hair follicles, and sweat glands of the skin
- Leave the superior cervical ganglion (SCG) of the prevertebral chain ganglia and follow the carotid arterial system into the head and neck to innervate
smooth muscle of blood vessels, the dilator pupillae muscle, the superior tarsal muscle, the lacrimal gland, the submandibular gland, the sublingual gland, and the parotid gland
- Leave the paravertebral chain ganglia (from the SCG → T4 levels) to enter the cardiac nerve plexus and pulmonary nerve plexus to innervate the heart and lung, respectively
- Leave prevertebral ganglia and the superior and inferior hypogastric plexuses to innervate smooth muscle of various visceral organs
- Modified postganglionic sympathetic neurons called chromaffin cells within the adrenal medulla release epinephrine (the majority product; 90%) and norepinephrine (the minority product; 10%) into the bloodstream, both of which are potent sympathetic neurotransmitters
INTERNEURONS
called small intensely fluorescent (SIF) cells
located in sympathetic ganglia
dopaminergic and inhibitory
NEUROTRANSMITTERS
Acetylcholine
preganglionic neurons
Norepinephrine
postganglionic sympathetic neurons
Epinephrine
Dopamine
FUNCTION
Responsible for control of stressed state: fight or flight
Results in large energy expenditure
Affects large number of structures :
dilator pupillae: dilates pupil
salivary glands: increased viscosity of saliva and decreased blood flow to the salivary glands resulting in less saliva
heart: accelerates rate and force
blood vessels: vasoconstricts
bronchioles: bronchodilates
digestive tract: inhibits motility
reproductive system: ejaculation
urinary system: activation
VISCEROSENSORY COMPONENT OF THE SYMPATHETIC
PAIN sensation - nociceptors - poorly localized
NEURONAL CHAIN :
- First neuron has its neuronal cell body located in the dorsal root ganglia at T1-L2/L3 spinal cord levels
This neuron sends a peripheral process to the viscera that ends as a
free nerve ending (or nociceptor) and sends a central process into the
spinal cord, which synapses with a second neuron within the spinal cord
- Second neuron (within the spinal cord) projects axons to the ventral posterolateral nucleus of the thalamus (VPL) and the reticular formation, where they synapse witha third neuron
- Third neuron (within the VPL and the reticular formation) projects axons to diverse areas of the cerebral cortex, hypothalamus, and intralaminar nuclei of the thalamus
PARASYMPATHETIC DIVISION - craniosacral owing to location of preganglionic cell bodies or cholinergic system - USES Ach
Responsible for control of the resting state; rest and repose
Responsible for energy conservation; reduces heart rate, increases digestion anabolic
Pre- and postganglionic cell bodies use acetylcholine as their neurotransmitter
CNS → long preganglionic neuron → ganglion → short postganglionic neuron → smooth muscle, cardiac muscle, and glands
VISCEROMOTOR COMPONENT OF THE PARASYMPATHETIC
PREGANGLIONIC PARASYMPATHETIC NEURON
CRANIAL DIVISION
OCULOMOTOR NERVE (CN III) - EDINGER-WESTPHAL NUCLEUS
Preganglionic axons from the Edinger-Westphal nucleus run with cranial nerve (CN) III and enter the ciliary ganglia, where they synapse with postganglionic neurons
Constriction of pupil and accommodation
FACIAL NERVE (CN VII) - LACRIMAL NUCLEUS & SUPERIOR SALIVATORY NUCLEUS
Preganglionic axons from the lacrimal nucleus run with CN VII and enter the pterygopalatine ganglion, where they synapse with postganglionic neurons
Preganglionic axons from the superior salivatory nucleus run with CN VII and enter the submandibular ganglion, where they synapse with postganglionic neurons
Lacrimation, increased oral and nasal mucosa secretion, increased saliva
GLOSSOPHARYNGEAL NERVE (CN IX) - INFERIOR SALIVATORY NUCLEUS
Preganglionic axons from the inferior salivatory nucleus run with CN IX and enter the otic ganglion, where they synapse with postganglionic neurons
Increased saliva
VAGUS NERVE (CN X) - DORSAL MOTOR NUCLEUS OF THE VAGUS NERVE
Preganglionic axons from the dorsal motor nucleus of the vagus nerve run with CN X and travel to various visceral organs (up to the splenic flexure of the mid-transverse colon), where they synapse with postganglionic neurons, cell bodies located in wall of target organ in thorax and abdomen
Intramural (terminal) ganglia
Increases gastric motility and secretion, slows heart rate, and causes bronchoconstriction
SACRAL DIVISION - GRAY MATTER OF THE S2 TO S4 SPINAL CORD
Preganglionic axons from the gray matter of the S2 to S4 spinal cord run as pelvic splanchnic nerves, which interact with the inferior hypogastric plexus and travel to various visceral organs (distal to the splenic flexure of the transverse colon), where they synapse with postganglionic neurons
preganglionic fibers travel in pelvic splanchnic nerves to intramural ganglia in wall of target organ
Lead to erection, urination, and an increase in gastric motility and secretion - micturition, defecation, and erection
POSTGANGLIONIC PARASYMPATHETIC NEURON
M1, M2, and M3 - smooth muscle, nodal tissue/cardiac muscle, and glands
- ciliary - sphincter pupillae muscle and ciliary muscle
- pterygopalatine - lacrimal glands and nasal glands
- submandibular - submandibular glands and sublingual glands
- otic - parotid
- X - various visceral organs
- pelvic splanchnic nerves innervate various visceral organs
VISCEROSENSORY COMPONENT OF THE PARASYMPATHETIC
CARRIES :
Arterial oxygen tension (PaO2) - arterial pH - chemoreceptors - carotid bodies
Blood pressure - baroreceptors - carotid sinus
Visceral pressure and movement sensation - rapidly adapting mechanoreceptors
Visceral stretch sensation - slowly adapting mechanoreceptors
Osmolarity - osmoreceptors
Temperature - internal thermal receptors
NEURONAL CHAIN :
- First - cell body located in
geniculate g CN VII - inferior (petrosal) g CN IX - inferior (nodose) g CN X - dorsal root ganglia S2 - S4
sends a peripheral
process to the viscera that ends at the chemor, baror, rapidly adapting
mechanor, slowly adapting mechanor, osmor, & internal thermal r
also send a central process into the brainstem or spinal cord, which synapses with a second neuron either in the solitary nucleus, dorsal horn of the spinal cord, or gray matter of the S2 to S4
- Second (in solitary nucleus) projects axons to the dorsal motor nucleus of the vagus nerve (DMN) and the rostral ventrolateral medulla (RVLM), where they synapse with a third
second neuron (in dorsal horn of the spinal cord) projects axons to the anterolateral system (ALS) and the spinoreticular tract, which terminate in the reticular formation
second neuron ( gray matter of the S2 to S4) is actually a preganglionic parasympathetic motor neuron of a pelvic splanchnic nerve (forming a sensory–motor reflex arc)
- Third neuron (in the DMN) is actually a preganglionic parasympathetic motor neuron of CN X (forming a sensory–motor reflex arc)
Third neuron (in the RVLM) projects axons to the intermediolateral cell column of the spinal and thereby controls the activity of preganglionic sympathetic motor neurons (forming a sensory–motor reflex arc)
ENTERIC DIVISION
VISCERAL AFFERENT FIBERS & PAIN - VISCEROSENSORY COMPONENT
Visceral afferent fibers ride with sympathetic & parasympathetic fiber-containing nerves
GVA FIBERS & INNERVATED STRUCTURES
GVA cell bodies
found in spinal ganglia, inferior ganglia of the glossopharyngeal nerve (CN IX) and the vagus nerve (CN X), and the geniculate ganglion of the facial nerve (CN VII)
GVA PAIN fibers
found in the white communicating rami
accompany nerves carrying sympathetic fibers
have their cell bodies in the spinal ganglia of the thoracolumbar region (Tl—L2)
GVA REFLEX fibers
accompany BOTH sympathetic & parasympathetic fibers
terminate centrally in the solitary nucleus
Carotid sinus
a dilation of the common carotid artery at the bifurcation
It contains baroreceptors; when stimulated, the receptors cause bradycardia and a decrease in blood pressure
innervated by GVA fibers from CN IX
Carotid body
a small structure just above the bifurcation of the common carotid artery; it contains chemoreceptors that respond to carbon dioxide, oxygen, and pH levels.
innervated by GVA fibers from CN IX and CN X
VISCERAL PAIN
Distension
Spasms or strong contractions
Mechanical stimulation
Myocardial ischemia
VISCERAL SOMATIC REFERRED PAIN
the false reference or localization of a painful visceral stimulus to a somatic dermatome of the same spinal cord segment
AUTONOMIC INNERVATION OF SELECTED ORGANS
Because the parasympathetic system is the energy conservation side of the ANS, it typically exerts more influence over systems than the sympathetic system,
although they work in tandem at all times
The postganglionic parasympathetic fibers are very short in the parasympathetic system
In true energy-saving fashion, they are able to activate discreet muscle groups;
postganglionic sympathetic fibers are relatively long, leading to massive and often not-situation-appropriate reactions to an emergency
EYE
Sympathetic input
Hypothalamic neurons
intermediolateral cell column
superior cervical ganglion
Miiller - ophthalmic artery
Horner syndrome
Parasympathetic input
nucleus
ciliary ganglion
Postganglionic fibers
internal ophthalmoplegia
BLOOD VESSELS
sympathetic
Arteries and arterioles
Large veins and venules
Cerebral blood vessels
HEART
Sympathetic input
intermediolateral cell column
rostral sympathetic trunk
Stimulation of cardiac nerves
Parasympathetic input
dorsal motor nucleus of the vagus
Postganglionic fibers
Vagal stimulation
BLADDER
Control is predominantly parasympathetic
Sympathetic input
Parasympathetic input
Somatomotor input
Sensory input to spinal cord
Ascending pathway for bladder sensation
Upper motor neuron input
SMOOTH MUSCLE
NODAL TISSUE/CARDIAC MUSCLE
GLANDS
OTHER
DISTRIBUTION
THORACIC SYMPATHETICS (T1–12)
LUMBOSACRAL SYMPATHETICS (L1–S5)
CERVICAL SYMPATHETICS (C1–8)
TYPICAL & SPECIFIC CONNECTIONS OF THE PARASYMPATHETIC GANGLIA
INVOLMENT OF CRANIAL NERVES IN AUTONOMIC DISTRIBUTION
PARASYMPATHETIC CONNECTION IN THE HEAD
SPECIAL PARASYMPATHETICS TO EYE
SPECIAL SYMPATHETICS TO EYE
DISTRIBUTION OF AUTONOMICS OF HEAD & NECK
ABDOMINAL AUTONOMICS
CLINICAL CORRELATIONS
Dysautonomia is a general term used to describe malfunction of the ANS
It may involve problems with the function of any of the multitude of structures innervated by the ANS
MEGACOLON (HIRSCHSPRUNG DISEASE OR CONGENITAL AGANGLIONIC MEGACOLON)
failure of neural crest cells to migrate into the colon
FAMILIAL DYSAUTONOMIA (RILEY–DAY SYNDROME)
autosomal recessive trait
loss of neurons in autonomic and sensory ganglia
RAYNAUD DISEASE
preganglionic sympathectomy
PEPTIC ULCER DISEASE
excessive production of hydrochloric acid
HORNER SYNDROME
SHY–DRAGER SYNDROME
BOTULISM
LAMBERT–EATON MYASTHENIC SYNDROME
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BRAINSTEM
(Kamina)
V1 PDF
INTRODUCTION
reticular formation
The brainstem is the phylogenetically oldest part of the brain
Cranially, it is continuous with the diencephalon, and caudally it is continuous with the spinal cord
In addition to providing an important conduit function, it contains circuitry for respiratory and cardiac reflex activity
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MEDULLA OBLONGATA (MYELENCEPHALON)
OVERVIEW MEDULLA
contains autonomic centers that regulate respiration, circulation, and gastrointestinal motility
extends from the pyramidal decussation to the inferior pontine sulcus
gives rise to cranial nerves—CN IX to CN XII
The nuclei of CN V and CN VIII extend caudally into the medulla
connected to the cerebellum by the inferior cerebellar peduncle
INTERNAL STRUCTURES OF MEDULLA
ASCENDING PATHWAYS & RELAY NUCLEI
Fasciculus gracilis and fasciculus cuneatus
Nucleus gracilis and nucleus cuneatus
Internal arcuate fibers
Decussation of the medial lemniscus
Medial lemniscus
Spinal lemniscus
contains the lateral & anterior spinothalamic tracts and the spinotectal tract
DESCENDING PATHWAYS
Pyramidal decussation
Pyramids
CEREBELLAR PATHWAYS & RELAY NUCLEI
Accessory (lateral) cuneate nucleus
Inferior olivary nucleus
cerebellar relay
nucleus that projects Olivocerebellar fibers Via the inferior
cerebellar peduncle to the contralateral cerebellar cortex and
cerebellar nuclei.
receives input from the red nucleus
Central tegmental tract
well-defined tract within the reticular formation
extends from the midbrain to the inferior olivary nucleus
contains rubro-olivary and reticulothalamic fibers
contains taste fibers
Lateral reticular nucleus
a cerebellar relay nucleus that projects Via the inferior cerebellar peduncle to the cerebellum
Arcuate nucleus
located on the anterior surface of the pyramids
gives rise to arcuatocerebellar fibers that become the striae medullares of the rhomboid fossa
Posterior spinocerebellar tract
Anterior spinocerebellar tract
Inferior cerebellar peduncle
CRANIAL NERVE NUCLEI & ASSOCIATED TRACTS
Medial longitudinal fasciculus (MLF)
Solitary tract
receives general visceral afferent (GVA) input from CN IX and CN X
receives special visceral afferent (SVA) (taste) input from CN VII, CN IX, and CN X
Solitary nucleus
projects GVA and
SVA input ipsilaterally via the central tegmental tract to the
parabrachial nucleus of the pons and to the ventral posteromedial
nucleus of the thalamus
Dorsal motor nucleus of CN X
Inferior salivatory nucleus of CN IX
Hypoglossal nucleus of CN XII
Nucleus ambiguus of CN IX & CN X
represents a special visceral efferent (SVE) cell column Whose axons innervate pharyngeal arch muscles of the larynx and pharynx
These fibers contribute to parts of CN IX and CN X; they exit the medulla via the postolivary sulcus
Spinal trigeminal tract
replaces the posterolateral tract (of Lissauer) of the spinal cord
contains
first-order neuron general somatic afferent (GSA) fibers that mediate
pain, temperature, and light touch sensations from the face via CNs V,
VII, IX, and X
projects to the spinal trigeminal nucleus
Spinal trigeminal nucleus
replaces the substantia gelatinosa of the spinal cord
gives rise to decussating axons that form the anterior trigeminothalamic tract
This tract terminates in the ventral posteromedial nucleus of the thalamus
Inferior and medial vestibular nuclei of CN VIII
receive proprioceptive (special somatic afferent [SSA]) input from the semicircular ducts, utricle, saccule, and cerebellum
project to the cerebellum and MLF
AREA POSTREMA
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PONS
OVERVIEW PONS
consists of the base that contains corticobulbar, corticospinal, and corticopontine tracts and pontine nuclei
and the tegmentum that contains cranial nerve nuclei, reticular nuclei, and the major ascending pathways
INTERNAL STRUCTURES OF PONS
ASCENDING PATHWAYS & RELAY NUCLEI
Dorsal and ventral cochlear nuclei
Trapezoid body
Superior olivary nucleus
Lateral lemniscus
Medial lemniscus
Spinal lemniscus
DESCENDING PATHWAYS (BASE)
Corticobulbar tract
Corticospinal tract (pyramidal tract)
Corticopontine tract
CEREBELLAR PATHWAYS & RELAY NUCLEI
Central tegmental tract
extends from the midbrain to the inferior olivary nucleus
contains rubro-olivary and reticulothalamic fibers
Juxtarestiform body
forms part of the inferior cerebellar peduncle
contains vestibulocerebellar, cerebellovestibular, and cerebelloreticular fibers
Middle cerebellar peduncle
contains pontocerebellar fibers
connects the pons to the cerebellum
Superior cerebellar peduncle
connects the cerebellum to the pons and midbrain
contains the dentatorubrothalamic fibers and the anterior spinocerebellar tract
Pontine nuclei
cerebellar relay nuclei in the base of the pons
give rise to pontocerebellar fibers that constitute the middle cerebellar peduncle
CRANIAL NERVE NUCLEI & ASSOCIATED TRACTS
Dorsal and ventral cochlear nuclei of CN VIII
Medial, lateral, and superior vestibular nuclei of CN VIII
Medial longitudinal fasciculus
Abducens nucleus of CN VI
pontine center for lateral conjugate gaze
Facial nucleus of CN VII
Superior salivatory nucleus of CN VII
Spinal trigeminal tract and nucleus of CN V
Trigeminal motor nucleus
Chief sensory nucleus of CN V
Mesencephalic nucleus and tract of CN V
LOCUS CERULEUS
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MESENCEPHALON (MIDBRAIN)
OVERVIEW
substantia nigra
paramedian reticular formation
STRUCTURES OF MIDBRAIN
Tectum
Tegmentum
Basis pedunculi (crus cerebri)
Pedunculus cerebri (cerebral peduncle)
Pretectum (pretectal area)
INFERIOR COLLICULAR LEVEL
Inferior colliculus
Nucleus of the inferior colliculus
Lateral lemniscus
Commissure of the inferior colliculus
Brachium of the inferior colliculus
Cerebral aqueduct
hydrocephalus
Periaqueductal gray matter contains several nuclear groups :
Locus ceruleus
Mesencephalic nucleus & tract
Dorsal tegmental nucleus contains enkephalinergic neurons that play a role in endogenous pain control.
Raphe nuclei contains serotonergic neurons
Trochlear nucleus of CN IV
Medial longitudinal fasciculus
Decussation of the superior cerebellar peduncles
lnterpeduncular nucleus
receives input from the habenular nuclei via the habenulointerpeduncular tract (fasciculus retroflexus of Meynert)
Substantia nigra
receives gamma-aminobutyric acidergic (GABA-ergic) input from the caudatoputamen (striatonigral fibers)
projects dopaminergic fibers to the caudatoputamen (nigrostriatal fibers)
projects
nondopaminergic fibers to the ventral anterior nucleus, ventral lateral
nucleus, and mediodorsal nucleus of the thalamus (nigrothalamic fibers)
Medial lemniscus
Spinal lemniscus
Central tegmental tract
contains rubro-olivary and reticulothalamic fibers
Basis pedunculi (crus cerebri)
SUPERIOR COLLICULAR LEVEL
Superior colliculus
Commissure of the superior colliculus
Brachium of the superior colliculus
Cerebral aqueduct and periaqueductal gray matter
Oculomotor nucleus of CN Ill
Accessory oculomotor (Edinger—Westphal) nucleus of CN Ill
Medial longitudinal fasciculus
Central tegmental tract
Red nucleus
located in the tegmentum at the level of the oculomotor nucleus (the level of the superior colliculus)
receives bilateral input from the cerebral cortex
receives contralateral input from the cerebellar nuclei
gives rise to the crossed rubrospinal tract
gives rise to the uncrossed rubro-olivary tract
exerts facilitatory influence on flexor muscles
Medial lemniscus
Spinal lemniscus
Substantia nigra
POSTERIOR COMMISSURAL LEVEL (PRETECTAL REGION)
a transition area between the mesencephalon and the diencephalon
Posterior commissure
interconnects pretectal nuclei, thus mediating consensual pupillary light reflexes
Pretectal nucleus
receives retinal input via the brachium of the superior colliculus
projects to the ipsilateral and contralateral accessory oculomotor nuclei, thus mediating the pupillary light reflexes
CORTICOBULBAR (CORTICONUCLEAR) FIBERS
arise from precentral and postcentral gyri
may synapse directly on motor neurons or indirectly via interneurons (corticoreticular fibers)
innervate sensory nuclei (gracile, cuneate, solitary, and trigeminal)
innervate cranial nerve motor nuclei bilaterally, With the exception ofpart ofthe facial nucleus (CN VII)
The upper face
division of the facial nucleus receives bilateral input; the lower face
division of the facial nucleus receives only contralateral input
innervate the
ipsilateral spinal nucleus of CN XI that supplies the
sternocleidomastoid and the contralateral spinal nucleus of CN XI that
innervates the trapezius
the orbicularis
oculi receives a variable number of crossed and uncrossed fibers; the
paresis therefore varies from patient to patient
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CRANIAL NERVES
(Kamina En général) V2 PDF
(Kamina Sommaire) V1 PDF
(Goldberg MRS Anatomy 2016 & Whitaker 2016) V1 PDF
SUMMARY TABLE OF NUCLEI & FIBRES OF CRANIAL NERVES
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NERVUS TERMINALIS (CN 0)
first
identified in humans approximately 100 years ago, often not included in
texts because of difficulty in identifying the nerve, its function, and
its origin
located anteromedial to the filia olfactoria, pierces the cribriform plate with CN 1
most likely a
special visceral afferent (SVA) nerve that mediates the perception of
pheromones and functions in reproductive systems
consists of unmyelinated nerve fibers associated With gyrus rectus
projects posteriorlyto the medial and lateral septal nuclei and the preoptic area ofthe diencephalon
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OLFACTORY I
GENERAL CHARACTERISTICS OF CN I
SVA
Bipolar olfactory neurons (in olfactory
epithelium in roof of
nasal cavity)
Smell (olfaction)
Central axons project to the
olfactory bulb via the cribriform
plate of the ethmoid bone
CLINICAL CORRELATION : CN I DAMAGE
anosmia
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OPTIC II
GENERAL CHARACTERISTICS OF CN II
SSA
Retinal ganglion cells
Vision and pupillary light reflexes
Central axons converge at the optic
disk and form the optic nerve, which
enters the skull via the optic canal
Optic nerve axons terminate primarily
in the lateral geniculate bodies
not a true peripheral nerve
CLINICAL CORRELATIONS : CN II
ipsilateral blindness and loss of direct pupillary light reflex
papilledema
optic atrophy
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OCULOMOTOR III
GENERAL CHARACTERISTICS OF CN III
moves the eye, constricts the pupil, and accommodates
GSE COMPONENT - MOTOR
Oculomotor nucleus
(rostral midbrain)
Medial rectus
Superior rectus
Interior rectus
Inferior oblique
Levator palpebrae
GVE COMPONENT - PARASYMPATHETIC
Composition
Pathway
Accessory oculomotor nucleus (rostral midbrain)
Ciliary ganglion
Sphincter pupillae,
ciliaris
Axons exit the midbrain into the
interpeduncularfossa,traverse
the cavernous sinus, and enter the
orbit via the superior orbital fissure
CLINICAL CORRELATIONS : CN III
OCULOMOTOR PARALYSIS
transtentorial herniation
diplopia
ptosis
look down and out
dilated and fixed pupil and paralysis of accommodation (cycloplegia)
OTHER CONDITIONS ASSOCIATED WITH CN III IMPAIRMENT
(uncal) herniation
Aneurysms (carotid and posterior communicating arteries)
Diabetes mellitus (diabetic oculomotor palsy)
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TROCHLEAR IV
GENERAL CHARACTERISTICS OF CN IV
Trochlear nucleus
(caudal midbrain)
GSE the superior oblique, depresses, intorts, and abducts
Axons decussate in superior
medullary velum, exit posteriorly
inferiorto the inferior colliculi,
encircle the midbrain, traverse the
cavernous sinus, and enterthe
orbit via the superior orbital fissure
CLINICAL CORRELATIONS : CN IV PARALYSIS
Extorsion of the eye and weakness of downward gaze
Vertical diplopia
Head tilting
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TRIGEMINAL V
GENERAL CHARACTERISTICS OF CN V
muscles of mastication and mediates general sensation
Ophthalmic division (Va)
Maxillary division (Vb)
Mandibular division (Vc)
GSA COMPONENT - SENSORY
Trigeminal ganglion
and mesencephalic
nucleus CN V (rostral
pons and midbrain)
Tactile, pain, and
thermal sensation
from the face;the oral
and nasal cavities and
the supratentorial dura
SVE COMPONENT - MOTOR
Trigeminal motor
nucleus (mid pons)
muscles of mastication tensor tympani tensor palati, mylohyoid, anterior belly of the digastric
Ophthalmic nerve exits via the
superior orbital fissure; maxillary nerve exits via the foramen
rotundum; mandibular nerve exits
via the foramen ovale; ophthalmic
and maxillary nerves traverse the
cavernous sinus; GSA fibers enter
the spinal trigeminal tract of CN V
CLINICAL CORRELATIONS : LESIONS OF CN V
Loss of general sensation
Loss of the corneal reflex
Flaccid paralysis of the muscles of mastication
Deviation of the jaw to the weak side
Paralysis of the tensor tympani
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ABDUCENS VI
GENERAL CHARACTERISTICS OF CN VI
GSE Abducens nucleus
(caudalpons) abducts the eye Lateral rectus
Axons exit the pons from the
inferior pontine sulcus, traverse
the cavernous sinus, and enterthe
orbit via the superior orbital fissure
CLINICAL CORRELATIONS : CN VI PARALYSIS
Convergent strabismus (esotropia)
Horizontal diplopia
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FACIAL VII
GENERAL CHARACTERISTICS OF CN VII
facial movements, taste, salivation, and lacrimation
facial nerve proper (motor division), which contains the SVE fibers
intermediate nerve (sensory division), which contains GSA, SVA, and GVE fibers
stomastoid foramen
Axons
exitthe pons in the cerebellar pontine angle and enterthe internal
auditory meatus; motor fibers traverse the facial canal of the temporal
bone and exit via the stylomastoid foramen; taste fibers traverse the
chorda tympani and lingual nerve; GSA fibers enter the spinal
trigeminal tract of CN V; SVA fibers enterthe solitarytract
GSA COMPONENT - SENSORY
Geniculate ganglion (temporal bone)
Tactile sensation to skin of ear posterior surface of the external ear
SVA COMPONENT - SENSORY
Geniculate ganglion
Taste sensation from the anterior two-thirds of tongue (via chorda tympani) taste buds
CHORDA TYMPANI
SVA and general visceral afferent (GVA)
GVE COMPONENT - PARASYMPATHETIC
Superior salivatory nucleus (caudal pons)
Lacrimal gland (via pterygopalatine ganglion submandibular and sublingual glands (via submandibular ganglion)
Lacrimal pathway
Submandibular pathway
SVE COMPONENT - MOTOR
Facial motor nucleus (caudal pons)
muscles of facial expression, the stylohyoid, the posterior belly of the digastric, and stapedius
CLINICAL CORRELATIONS : LESIONS OF CN VII
Flaccid paralysis
Loss of the corneal (blink) reflex
Loss of taste
Hyperacusis
Bell's palsy
facial palsy
Crocodile tears syndrome
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VESTIBULOCOCHLEAR VIII
SSA
Vestibular and cochlear nerves join in the internal auditory meatus and enterthe brain stem in the cerebellopontine angle
vestibular nerve projects to the vestibular nuclei andthe flocculonodular lobe of the cerebellum
cochlear nerve projects to the cochlear nuclei
VESTIBULAR NERVE
GENERAL CHARACTERISTICS
Vestibular ganglion (internal auditory meatus)
Equilibrium (innervates hair cells of semicircular ducts, saccule, and utricle)
equilibrium and balance
compensatory eye movements
CLINICAL CORRELATIONS : LESIONS
disequilibrium, vertigo, and nystagmus
COCHLEAR NERVE
GENERAL CHARACTERISTICS
Spiral ganglion (modiolus of temporal bone)
Hearing (innervates hair cells of the organ of Corti)
CLINICAL CORRELATIONS : LESIONS
hearing loss
tinnitus
TOC
GLOSSOPHARYNGEAL IX
GENERAL CHARACTERISTICS OF CN IX
Axons exit (motor) & enter (sensory) medulla from the postolivary sulcus; axons exit and enter the skull via jugular foramen
GSA fibers enterthe spinal trigeminal tract of CN V; GVA and SVA fibers enter the solitary tract
taste (gustation), salivation, and (with CN X and CN XII) swallowing
input from the carotid sinus
input from the carotid body
GSA COMPONENT - SENSORY
Superior ganglion (jugular foramen)
Tactile sensation to middle ear cavity
GVA COMPONENT - SENSORY
Inferior (petrosal) ganglion (in jugular foramen)
Tactile sensation to posteriorthird of tongue, pharynx, middle ear, and auditory tube; input from carotid sinus and carotid body
SVA COMPONENT - SENSORY
Inferior (petrosal) ganglion (in jugular foramen)
Taste from posterior third of thetongue
SVE COMPONENT - MOTOR
Nucleus ambiguus (rostral medulla)
Stylopharyngeus
GVE COMPONENT - PARASYMPATHETIC
Inferior salivatory nucleus (rostral medulla)
Parotid gland (via the otic ganglion)
CLINICAL CORRELATIONS : LESIONS OF CN IX
TOC
VAGUS X
GENERAL CHARACTERISTICS OF CN X
GSA, GVA, SVA, SVE, and GVE components
phonation, swallowing (with CN IX and CN XII), elevation of the palate, and taste
viscera of the neck, thorax, and abdomen
Axons
exit (motor) and enter (sensory) medulla from the postolivary sulcus;
axons exit and enterthe skull via the jugular foramen;
GSA fibers enter the spinal trigeminal tract of CN V;
GVA and SVA fibers enter the solitary tract
GSA COMPONENT - SENSORY
Superior ganglion (jugularforamen)
Tactile sensation to the external ear
SVA COMPONENT - SENSORY
lnferior (nodose) ganglion (in jugular foramen)
Taste from the epiglottis
GVA COMPONENT - SENSORY
Inferior (nodose) ganglion (in jugular foramen)
Mucous membranes of the pharynx, larynx, esophagus, trachea, and thoracic and abdominal viscera to the midtransverse colon
SVE COMPONENT - MOTOR
Nucleus ambiguus (midmedulla)
Muscles of the larynx and pharynx
GVE COMPONENT - PARASYMPATHETIC
Dorsal motor nucleus of CN X (medulla)
Viscera of the thoracic and abdominal cavities to the midtransverse colon (via terminal [intramural] ganglia)
CLINICAL CORRELATIONS : LESIONS OF CN X
TOC
ACCESSORY XI
SVE fibers
head and shoulder movement
sternocleidomastoid (with C2) and trapezius (with C3 and C4)
Axons exit the spinal cord, ascend through the foramen magnum, and exit the skull via the jugular foramen
GENERAL CHARACTERISTICS OF CN XI
SVE - MOTOR
Anterior horn neurons C1—C6
CLINICAL CORRELATIONS : LESIONS OF CN XI
Paralysis of the sternocleidomastoid
Paralysis of the trapezius
TOC
HYPOGLOSSAL XII
tongue movement
pure GSE nerve
intrinsic and extrinsic muscles of the tongue
Axons exit from the preolivary sulcus of the medulla and exit the skull via the hypoglossal canal
GENERAL CHARACTERISTICS OF CN XII
GSE
Hypoglossal nucleus (medulla)
Intrinsic and extrinsic muscles of the tongue (except the palatoglossus)
CLINICAL CORRELATIONS : CN XII
TOC
TRIGEMINAL SYSTEM
GENERAL CHARACTERISTICS OF CN V
muscles of mastication and mediates general sensation
Ophthalmic division (Va)
Maxillary division (Vb)
Mandibular division (Vc)
GSA COMPONENT - SENSORY
Trigeminal ganglion
and mesencephalic
nucleus CN V (rostral
pons and midbrain)
Tactile, pain, and
thermal sensation
from the face;the oral
and nasal cavities and
the supratentorial dura
SVE COMPONENT - MOTOR
Trigeminal motor
nucleus (mid pons)
muscles of mastication tensor tympani tensor palati, mylohyoid, anterior belly of the digastric
Ophthalmic nerve exits via the
superior orbital fissure; maxillary nerve exits via the foramen
rotundum; mandibular nerve exits
via the foramen ovale; ophthalmic
and maxillary nerves traverse the
cavernous sinus; GSA fibers enter
the spinal trigeminal tract of CN V
CLINICAL CORRELATIONS : LESIONS OF CN V
Loss of general sensation
Loss of the corneal reflex
Flaccid paralysis of the muscles of mastication
Deviation of the jaw to the weak side
Paralysis of the tensor tympani
TRIGEMINAL NERVE (CN V)
ophthalmic, maxillary, and mandibular
THE TRIGEMINAL GANGLION (SEMILUNAR OR GASSERIAN)
is homologous to a spinal ganglion, containing pseudounipolar primary afferents
Ophthalmic nerve (CN V1)
cavernous sinus
superior orbital fissure
corneal blink reflex
Maxillary nerve (CN V2)
cavernous sinus
foramen rotundum
Mandibular nerve (CN V3)
foramen ovale
muscles of mastication mylohyoid anterior belly of the digastric tensor tympani and tensor palati
CN V VII IX X
contribute sensory fibers to the ear, middle ear cavity (CN IX), and external ear (CNs V, IX, and X)
SPINAL TRIGEMINAL TRACT
(tractotomy)
projects to the spinal trigeminal nucleus as follows
Pain fibers
Corneal reflex fibers
The trigeminal sensory system is responsible for all of the various sensory modalities for the face and much of the head, excluding special senses
ASCENDING TRIGEMINOTHALAMIC TRACTS
ANTERIOR TRIGEMINOTHALAMIC TRACT
(VPM)
First-order neurons
Second-order neurons
Third-order neurons
POSTERIOR TRIGEMINOTHALAMIC TRACT
First-order neurons
Second-order neurons
Third-order neurons
TRIGEMINAL SENSORY NUCLEI
CHIEF (PRINCIPAL, MAIN) SENSORY NUCLEUS
SPINAL TRIGEMINAL NUCLEUS
MESENCEPHALIC NUCLEUS
GSA proprioception
is the only population of pseudounipolar, first-order cell bodies in the CNS
It is important in the jawjerk reflex and used by humans primarily as infants for suckling
TRIGEMINAL MOTOR NUCLEUS SVE
TRIGEMINOCEREBELLAR FIBERS
PAIN & TEMPERATURE & TOUCH / SPINAL TRIGEMINAL TRACT & NUCLEUS
DESCRIPTION
Peripheral processes of first-order neurons end as free nerve endings or contact Merkel disks;
first-order cell bodies are in the trigeminal, geniculate, glossopharyngeal, or vagal ganglia;
central processes enter the brainstem via the trigeminal (CN V), facial
(CN VII), glossopharyngeal (CN IX), or vagus (CN X) nerves;
fibers ascend or descend via the spinal trigeminal tract to synapse on second-order neurons of the spinal trigeminal nucleus (C3-midpons) located immediately medial to the tract
Second-order fibers cross the midline to ascend to the VPM of the thalamus as the anterior trigeminothalamic tract;
fibers also send axon collaterals to the brainstem reticular formation
Third-order
neurons in the VPL of the thalamus project to the postcentral gyrus:
primary sensory cortex (areas 3, 1, 2) via the posterior limb of
internal capsule
FUNCTIONS
The spinal trigeminal tract is a homolog of the posterolateral tract
The spinal trigeminal tract allows first-order central processes to ascend or descend: pain, caudal 1/3; touch, cranial 2/3
FINE TOUCH, CONSCIOUS PROPRIOCEPTION & VIBRATORY SENSE / TRIGEMINAL GANGLION
DESCRIPTION
Peripheral processes of first-order neurons innervate Pacinian and Meissner corpuscles;
first-order cell bodies are in the trigeminal, geniculate, glossopharyngeal, or vagal ganglia;
central processes terminate on second-order neurons in the principal sensory nucleus
Second-order fibers cross the midline to ascend as part of the anterior trigeminothalamic tract to the VPM of the thalamus;
fibers from the oral region travel bilaterally;
those travelling ipsilaterally form the small posterior trigeminothalamic tract to terminate in the ipsilateral thalamus
Third-order
neurons in the VPL of the thalamus project to the postcentral gyrus:
primary sensory cortex (areas 3, 1, 2) via the posterior limb of
internal capsule
FUNCTIONS
Functions similarly to the posterior columns of the spinal cord
The principal sensory nucleus is also known as the chief sensory nucleus
UNCONSCIOUS PROPRIOCEPTION / MESENCEPHALIC TRACT & NUCLEUS
DESCRIPTION
Peripheral fibers of cells in the mesencephalic nucleus innervate muscles spindles and Golgi tendon organs
Central processes project to the cerebellum and innervate the trigeminal motor nucleus to mediate reflexes and chewing
FUNCTIONS
Mediates unconscious or reflex proprioception from the temporomandibular joint, periodontal ligaments, and facial musculature
TRIGEMINAL REFLEXES
JAW JERK MASSETER REFLEX
afferent limb (CN V3)
efferent limb (CN V3)
CORNEAL REFLEX
afferent limb (CN V1 motor)
efferent limb (CN VII)
LACRIMAL TEARING REFLEX
afferent limb (CN V1)
efferent limb (CN VII)
CLINICAL CORRELATIONS
TRIGEMINAL NEURALGIA (TIC DOULOUREUX)
sharp, stabbing pain
Carbamazepine, a tricyclic compound related to imipramine
HERPES ZOOSTER OPHTHALMICUS
PARATRIGEMEINAL ( RAEDER ) SYNDROME
CENTRAL LESIONS OF SPINAL TRIGEMINAL TRACT & NUCLEUS
loss of sensation, occurring in an onion-skin distribution
ACOUSTIC NEUROMA (SCHWANOMMA)
tinnitus and unilateral hearing loss
facial weakness and loss of corneal blink reflex
loss of pain and temperature sensation and loss of the corneal blink reflex
CAVERNOUS SINUS SYNDROME
Ocular motor nerves CNs III, IV, and VI
internal ophthalmoplegia
Trigeminal nerve branches of CN V1 and CN V2
Postganglionic sympathetic fibers to the orbit
Horner syndrome
TOC
LESIONS OF THE BRAINSTEM
INTRODUCTION
most frequently syndromes of arterial occlusion or circulatory insufficiency that involve the vertebrobasilar system
VASCULAR LESIONS OF THE MEDULLA
result
from occlusion of the vertebral artery or its branches (e.g., the
anterior and posterior spinal arteries and the posterior inferior
cerebellar artery [PICA]
MEDIAL MEDULLARY SYNDROME (ANTERIOR SPINAL ARTERY SYNDROME)
structures deficits
Corticospinal tract
Medial lemniscus
Hypoglossal nerve roots (intra-axial fibers)
LATERAL MEDULLARY (WALLENBERG; POSTERIOR INFERIOR CEREBELLAR ARTERY [PICA]) SYNDROME
structures deficits
Vestibular nuclei (medial and inferior)
Interior cerebellar peduncle
Nucleus ambiguus of CNs IX and X
Glossopharyngeal nerve roots (intra-axial fibers)
Vagal nerve roots (intra-axial fibers)
Spinothalamic tracts
Spinal trigeminal nucleus and tract
Descending sympathetic tract
VASCULAR LESIONS OF THE PONS
result
from occlusion ofthe basilar artery or its branches (e.g., the anterior
inferior cerebellar artery [AICA], transverse pontine arteries, or
superior cerebellar artery)
MEDIAL INFERIOR PONTINE SYNDROME
structures deficits
Abducens nerve roots (intra-axial fibers)
Corticobulbar tracts
Corticospinal tracts
Base of the pens (middle cerebellar peduncle)
Medial lemniscus
LATERAL INFERIOR PONTINE SYNDROME AICA SD
structures deficits
Facial motor nucleus and intra-axial nerve fibers
Cochlear nuclei and intra-axial nerve fibers
Vestibular nuclei and intra-axial nerve fibers
Spinal trigeminal nucleus and tract
Middle and inferior cerebellar peduncles
Spinothalamic tracts
Descending sympathetic tract
LATERAL MIDPONTINE SD
structures deficits
Trigeminal nuclei and nerve root (motor and principal sensory nuclei)
Paralysis of the muscles of mastication
Jaw deviation to the paretic side
Facial hemianesthesia
Loss of the corneal reflex
Middle cerebellar peduncle (base of the pons)
LATERAL SUPERIOR PONTINE SD
superior cerebellar artery
structures deficits
Superior and middle cerebellar peduncles
Dentate nucleus
Spinothalamic and trigeminothalamic tracts
Descending sympathetic tract
Medial lemniscus (lateral division [gracilis])
LOCKED IN SD PSEUDOCOMA
central pontine myelinolysis
FACIAL COLLICULUS SYNDROME
LESIONS OF THE MIDBRAIN
result from vascular occlusion of the mesencephalic branches of the posterior cerebral artery
may be the outcome of aneurysms of the posterior cerebral arterial circle
may result from tumors of the pineal region
may occur owing to hydrocephalus
POSTERIOR MIDBRAIN (PARINAUD) SYNDROME
pinealoma or germinoma
structures deficits
Superior colliculus and pretectal area
Cerebral aqueduct
PARAMEDIAN MIDBRAIN (BENEDIKT) SYNDROME
structures deficits
Oculomotor nerve roots (intra-axial fibers)
ipsilateral oculomotor paralysis
eye abduction and depression
fixed and dilated pupil
Red nucleus and dentatorubrothalamic tract
Medial lemniscus
MEDIAL MIDBRAIN (WEBER) SYNDROME
structures deficits
Oculomotor nerve roots (intra-axial fibers)
Corticobulbar tracts
Corticospinal tracts
DECEREBRATE & DECORTICATE RIGIDITY
Descending vestibulospinal and pontoreticulospinal pathways play an important role in the control of extensor muscle tone
Transection of the brainstem or decortication results in a tremendous increase in antigravity tone
Decerebrate rigidity (posturing)
opisthotonos
gamma rigidity
Decorticate rigidity (posturing)
bilateral spastic hemiplegia
ACOUSTIC NEUROMA (SCHWANNOMA)
structures deficits
Cochlear Division of CN VIII
Vestibular Division of CN VIII
Facial Nerve (CN VII)
Spinal Tract of Trigeminal Nerve (CN V)
Abducens nerve CN VI in advanced cases with large tumors
Corticospinal tract in advanced cases with large tumors
MLF SYNDROME INTERNUCLEAR OPHTHALMOPLEGIA
JUGULAR FORAMEN (VERNET) SYNDROME
Glossopharyngeal Nerve (CN IX)
Vagal Nerve (CN X)
Accessory Nerve (CN XI)
SUBCLAVIAN STEAL SYNDROME
results from thrombosis of the left subclavian artery proximal to the vertebral artery.
Blood is shunted in the left vertebral artery and into the left subclavian artery.
Clinical signs
include transient weakness and claudication of the left upper limb on
exercise and vertebrobasilar insufficiency (i.e., vertigo, dizziness)
The Cerebellopontine Angle
“Top of the Basilar” Syndrome
TOC
CEREBELLUM
(Kamina)
V1 PDF
The cerebellum is involved in the planning, coordination, and modification of motor activities
The cerebellum coordinates complex motor movements and is involved in motor learning and skilled planned motor activity
It does not initiate motor activity; rather, it controls or influences the strength, timing, and accuracy of ongoing motor activity
It is located in infratentorially in the posterior cranial fossa
AFFERENT
Vestibular nuclei → Vestibulocerebellar tract → ICP → Cerebellum → Granule cell
Pontine nuclei → Pontocerebellar fibers → MCP → Deep cerebellar nuclei → Granule cell
Inferior olivary nucleus → Olivocerebellar tract → ICP → Hemisphere → Purkinje cell → Deep cerebellar nuclei
EFFERENT
Dentate nucleus in Lateral hemisphere/pontocerebellum → SCP → Dentatothalamic tract → Thalamus (VL) → Motor cortex
Interposed nucleus in Intermediate hemisphere/spinocerebellum → SCP → Reticular formation, or → Cerebellothalamic tract → Red nucleus → Thalamus (VL) → Motor cortex
Fastigial nucleus in Flocculonodular lobe/vestibulocerebellum → Vestibulocerebellar tract → Vestibular nuclei
BIDIRECTIONAL : SPINOCEREBELLAR
Unconscious proprioception
lower limb → 1° (muscle spindles = MS → DRG) → 2° (Posterior thoracic nucleus → Dorsal/posterior spinocerebellar tract → ICP → Cerebellar vermis)
upper limb → 1° (muscle spindles → DRG) → 2° (Accessory cuneate nucleus → Cuneocerebellar tract → ICP → Anterior lobe of cerebellum)
Reflex arc
lower limb → 1° (Golgi tendon organ = GTO) → 2° (Ventral/anterior spinocerebellar tract→ SCP → Cerebellar vermis)
upper limb → 1° (Golgi tendon organ) → 2° (Rostral spinocerebellar tract → ICP → Cerebellum)
OVERVIEW - FUNCTION
Maintenance of Posture & Balance
Maintenance of Muscle Tone
Coordination of Voluntary Motor Activity
MAJOR DIVISIONS OF THE CEREBELLUM - ANATOMY
vermis - hemispheres
cortex
white matter
4 nuclei = dentate + (emboliform + globose = interposed) + fastigial
WHITE MATTER = INTERNAL (ARBOR VITAE) + PEDUNCLES
GREY MATTER = NUCLEI + CORTEX
LOBES - LATERAL-ANTERIOR TO POSTERIOR DIVISIONS
Anterior lobe (spinocerebellum)
Anterior is separated from posterior by a primary fissure
Posterior lobe (neocerebellum)
Posterior is separated from flocculonodular by a posterolateral fissure
Flocculonodular lobe (vestibulocerebellum)
LONGITUDINAL ORGANIZATION OF THE CEREBELLUM - LATERAL TO MEDIAL DIVISIONS - MEDIAL/LATERAL
Lateral-to-medial divisions are based on functional connections
Median (vermal) zone
Paramedian (paravermal) zone
Lateral zone
CEREBELLAR PEDUNCLES
Connect the cerebellum to the brainstem, mainly the pons
INFERIOR CEREBELLAR PEDUNCLE = ICP (MEDULLA)
Connects cerebellum to rostral medulla
Two parts
Mixture of cerebellar afferents and efferents, mostly input from the spinal cord
RESTIFORM BODY
Posterior spinocerebellar tract
Cuneocerebellar tract
Olivocerebellar tract
JUXTARESTIFORM BODY
Vestibulocerebellar fibers (afferent)
Cerebellovestibular fibers (efferent)
MIDDLE CEREBELLAR PEDUNCLE = MCP (PONS)
Connects cerebellum to pons
Major input pathway to cerebellum
pontocerebellar fibers
SUPERIOR CEREBELLAR PEDUNCLE = SCP (MIDBRAIN)
Connects cerebellum to caudal midbrain and pons
Major outflow pathway from cerebellum
EFFERENT PATHWAYS
Dentatorubrothalamic tract
lnterpositorubrothalamic tract
Fastigiothalamic tract
Fastigiovestibular tract
AFFERENT PATHWAYS
Anterior spinocerebellar tract
Trigeminocerebellar fibers
Ceruleocerebellar fibers
CEREBELLAR CORTEX, NEURONS, & FIBERS
THE CEREBELLAR CORTEX HAS 3 LAYERS
From outside to in, the cerebellar cortex is divided into a molecular layer, Purkinje cell layer, and a granule cell layer
MOLECULAR LAYER - Stellate cell - Basket cell
Contains Purkinje cell dendritic tree
Contains parallel fibers of granule cells
Contains stellate and basket cells
Site of granule cell excitatory synapse on Purkinje cell
PURKINIE CELL LAYER - Purkinje cell - Bergmann glia cell = Golgi epithelial cell - Fañanas cell
Contains Purkinje cell bodies
Purkinje cells represent the only outflow from the cerebellar cortex, always inhibitory (release γ-aminobutyric acid [GABA]); project to deep cerebellar nuclei & vestibular nuclei
Excited by parallel and climbing fibers from olivocerebellar tract
Inhibited by basket and stellate cells
GRANULE CELL LAYER - Golgi cell - Granule cell - Unipolar brush cell
cerebellar glomeruli
Contains granule and Golgi cells
Granule cells excite (glutamate) Purkinje, basket, stellate, and Golgi cells
Granule cells are inhibited by Golgi cells
Granule cells are excited by mossy fibers (excitatory fibers from spino- and pontocerebellar tracts)
NEURONS & FIBERS OF THE CEREBELLUM
PURKINJE CELL
GRANULE CELL
MOSSY FIBERS = MF
spinocerebellar & pontocerebellar tracts
CLIMBING FIBERS = CF
olivocerebellar tract
PARALLEL FIBER = PF
FUNCTIONAL CEREBELLUM & DEEP NUCLEI
Functionally, the cerebellum can be divided in terms of its involvement in primitive to more advanced movements;
such a system includes the deep cerebellar nuclei associated with each division
ANTERIOR L - SPINAL CBL
Interposed Nuclei (Globose & Emboliform)—associated with the 2 PALEOcerebellum deal with walking & arm movements - Locomotion Walking, running
-Primary Fissure-
POSTERIOR L - CEREBRAL CBL
Dentate Nucleus—the most lateral and the largest, is part of the 3 NEOcerebellum and is associated with highly skilled movements, such as stacking a house of cards - Fine movement:
Playing piano, writing
Gives rise to dentatothalamic tract
-Posterolateral Fissure-
FN L - VESTIBULAR CBL
Fastigial Nucleus—the most midline nucleus is associated with the 1 ARCHIcerebellum and deals with balance & equilibrium - Balance: sitting upright
PHYLOGENETIC DIVISIONS
VESTIBULOCEREBELLUM
Also known as archicerebellum
Pathway begins in inner ear; travels on CN VIII to vestibular nuclei in pons, fastigial nucleus, and flocculonodular lobe
Flocculonodular
lobe also receives input from superior colliculus (visual information)
and striate cortex (visual); projects back out to vestibular nuclei
Posture, balance and equilibrium, and eye movements
Allows cerebellum to coordinate eye movements with head movement and position to keep images focused on retina
SPINOCEREBELLUM
Also known as paleocerebellum
Receives input from spinal cord and inner ear; also from mesencephalic nucleus and cuneocerebellar fibers (upper limb) to the interposed nuclei (globose and emboliform)
Posture, muscle tone, timing, and accuracy of ongoing movements, particularly in the trunk and limb girdles
Reciprocal connections with spinal cord allows cerebellum to influence descending spinal cord control mechanisms
NEOCEREBELLUM
Also known as pontocerebellum
Receives both motor and sensory information from cerebral cortex
Information from cortex relays in pons (pontocerebellar fibers)
Dentatorubrothalamic tract projects back out to the red nucleus and thalamus
Skilled, learned movements; hand–eye coordination with appropriate strength, timing, and precision
Cerebellum to red nucleus allows influence over all descending cortical fibers to influence volitional movements
The red nucleus projects to the inferior olivary nucleus via the central tegmental tract, which projects back to the cerebellum, forming a loop or closed circuit
Such cerebellar
“circuits,” whereby the cerebellar circuit is connected to the
descending pathway, allow for the cerebellum to influence the
descending pathway based on incoming information from the spinal cord,
visual system, and inner ear
THE MAJOR CEREBELLAR CIRCUIT
Influences ongoing motor activity
It consists of the following structures
The Purkinje cells of
the cerebellar cortex project to the deep cerebellar nuclei (e.g.,
dentate, interposed (emboliform and globose), and fastigial nuclei)
The dentate nucleus is the major effector nucleus of the cerebellum in humans
It gives rise to
the dentatothalamic tract, which projects through the superior
cerebellar peduncle to the contralateral ventral lateral nucleus of the
thalamus
The decussation of the superior cerebellar peduncle is in the caudal midbrain tegmentum
The ventral lateral nucleus of the thalamus receives the dentatothalamic tract
It projects to the primary motor cortex of the precentral gyrus (Brodmann area 4)
The motor cortex (Brodmann area 4) receives input from the ventral lateral nucleus of the thalamus
It projects as the corticopontine tract to the pontine nuclei
The pontine nuclei receive input from the motor cortex
Axons project as the pontocerebellar tract to the contralateral
cerebellar cortex, where they terminate as mossy fibers, thus
completing the circuit
MAJOR CEREBELLAR PATHWAYS
VESTIBULO-CEREBELLAR PATHWAY
Semicircular ducts and otolith organs
Flocculonodular lobe
Vestibular nuclei
VERMAL SPINO-CEREBELLAR PATHWAY
Vermis
Fastigial nucleus
Ventral lateral nucleus of the thalamus
Precentral gyrus
anterior corticospinal tract
PARAVERMAL SPINO-CEREBELLAR PATHWAY
Paravermis
lnterposed nuclei (emboliform and globose)
Ventral lateral nucleus - lateral corticospinal tract
Red nucleus - rubrospinal tract
LATERAL HEMISPHERIC CEREBELLAR PATHWAY
neocerebellar or pontocerebellar pathway
CEREBELLAR HEMISPHERE
corticopontocerebellar tract
DENTATE NUCLEUS
Red nucleus pathway
red nucleus
interior olivary nucleus
Ventral lateral nucleus pathway
ventral lateral nucleus
motor and premotor cortices
Corticobulbar tract
Lateral corticospinal tract
Corticopontocerebellartracts
Interior olivary nucleus pathway
receives direct input from the dentate nucleus
projects directly to the dentate nucleus
CEREBELLAR DYSFUNCTION
HYPOTONIA
DISEQUILIBRIUM
DYSSYNERGIA
Dysarthria
Dystaxia
Dysmetria
Intention tremor
Dysdiadochokinesia
Nystagmus
Decomposition of movement (by-the-numbers phenomenon)
Rebound or lack of check
CEREBELLAR LESIONS - SYNDROMES AND TUMORS - CLINICAL SIGNIFICANCE
Lesions of the flocculonodular lobe or archicerebellar lesions lead to truncal disequilibrium; gait and the trunk are affected
This causes a person to walk on a wide-base, with the trunk swaying when walking
Individuals are unsteady when standing, tend to stagger, and may appear drunk
Possible causes are a cerebellopontine angle tumor or lateral medullary syndrome (i.e., blockage of the posterior inferior cerebellar artery)
Lesions of the anterior lobe or paleocerebellum lesions are often related to alcoholism or malnutrition
The symptoms appear as gross deficits, mainly affecting the trunk and legs
The most prominent signs include dystaxia (ataxia)—poor
coordination of muscles of gait and stance that cause the legs to be
uncoordinated—and dystaxia (ataxia) of the trunk, causing the trunk to
bob to-and-fro when walking
Lesions of the neocerebellum or lateral hemisphere are often unilateral and may combine with anterior lobe and vermal symptoms
Lesions of the
cerebellar hemispheres, dentate nucleus (anterior inferior cerebellar
artery), or superior cerebellar peduncle (dentatorubrothalamic tract)
may also affect speech and eye movement
Symptoms are most obvious in the upper extremity in rapid, fine movements
ANTERIOR VERMIS SYNDROME
POSTERIOR VERMIS SYNDROME
HEMISPHERIC SYNDROME
PHENYTOIN (ANTIEPILEPTIC DRUG)
TUMORS OF THE CEREBELLUM
Astrocytomas
Medulloblastomas
Ependymomas
CEREBELLAR ATROPHIES
Friedreich ataxia
subacute combined degeneration
Cerebello-olivary degeneration (Holmes disease)
Olivopontocerebellar degeneration (Deierine—Thomas syndrome)
TOC
DIENCEPHALON, THALAMUS, HYPOTHALAMUS & HYPOPHYSIS
(Kamina)
V1 PDF
HYPOPHYSIS
(Kamina)
V1 PDF
The diencephalon is located immediately cranial to the brainstem & between the cerebral hemispheres
(DORSAL) THALAMUS
Extends
anteriorly to the anterior commissure, inferiorly to the hypothalamic
sulcus, and posteriorly to the posterior commissure
Thalami are separated by the third ventricle
All sensory information, except olfaction, connects with the thalamus as it passes to the cerebral cortex
HYPOTHALAMUS
Extends superiorly to the hypothalamic sulcus
Coordinates drive-related behaviors through control of the autonomic nervous system and maintains homeostasis
EPITHALAMUS
Posterior-most part of the diencephalon
Primary components are the pineal gland and habenula
SUBTHALAMUS
Primary component is the subthalamic nucleus
Functionally related to the basal nuclei
TOC
INTRODUCTION : THE THALAMUS
largest division of the diencephalon
receives precortical input from all sensory systems except the olfactory system
largest input received is from the cerebral cortex
projects primarily to the cerebral cortex and to a lesser degree to the basal nuclei and hypothalamus
plays an important role in sensory and motor system integration
The largest part of the diencephalon, the dorsal thalamus—or, more
commonly, the thalamus—consists of two large ovoid groups of nuclei,
typically interconnected by an interthalamic adhesion
The thalami receive most of the input from the basal nuclei and all sensory input except for olfaction
BOUNDARIES OF THE THALAMUS
Anterior : interventricular foramen
Posterior : free pole of pulvinar
Dorsal : free surface underlying the fornix and the lateral ventricle
Ventral : plane connecting the hypothalamic sulci
Medial : third ventricle
Lateral : posterior limb of the internal capsule
PRIMARY THALAMIC NUCLEI & THEIR MAJOR CONNECTIONS 1 input 2 output
ANTERIOR ANT
Hypothalamus via mamillothalamic tract and hippocampus via fornix
Cingulate gyrus
MEDIAL DM MD memory loss
Prefrontal and orbital cortex and intralaminar nuclei
Prefrontal and orbital cortex, amygdala, and temporal cortex
INTRALAMINARI
CM
is the largest intralaminar nucleus
It is reciprocally connected to the motor cortex (Brodmann area 4)
The centromedian nucleus receives input from the globus pallidus
It projects to the striatum (caudate nucleus and putamen) and projects diffusely to the entire neocortex
PF
projects to the striatum and the supplementary motor cortex (area 6)
plays a role in changing patterns of response to stimuli
LATERAL
DORSAL TIER
LD
Mamillothalamic tract
Cingulate gyrus
LP
Parietal cortex (areas 1 and 5)
PUL
Association cortex of the parietal, occipital, and temporal lobes; medial and lateral geniculate nuclei; and superior colliculus
Association cortex of parietal, occipital, and temporal lobes
VENTRAL TIER
VA
Basal nuclei
Motor cortex (areas 4 and 6)
VL
Basal nuclei, cerebellum and red nucleus
Motor cortex (areas 4 and 6)
VP
VPL
Spinothalamic tracts and medial lemniscus
Sensory cortex (areas 3, 1 and 2)
VPM
Trigeminothalamic tracts, taste (solitary nucleus)
Sensory cortex (areas 3, 1 and 2)
LGB
Retina > Optic tract
Primary visual cortex (area 17) via the optic radiations
MGB
Cochlear nerve > Inferior colliculus
Primary auditory cortex (areas 41 and 42)
TRN reticular
All thalamic nuclei
MIDLINE
Motor cortex (area 4) and globus pallidus
Motor cortex (area 4), striatum, and diffuse to entire cortex
BLOOD SUPPLY OF THE THALAMUS
Posterior Communicating Artery
Posterior Cerebral Artery
Anterior Choroidal Artery (Lateral Geniculate Body)
TOC
INTERNAL CAPSULE
Anterior limb
Genu
Posterior limb
Retrolenticular part
Sublenticular part
BLOOD SUPPLY OF THE INTERNAL CAPSULE
Anterior limb
Genu
Posterior limb
CLINICAL CORRELATIONS
Infarction
Tactile hypesthesia
Anesthesia
Hemiparesis (with Babinski sign)
Lowerfacial weakness
Homonymous hemianopia
Thalamic sd
TOC
OVERVIEW : THE HYPOTHALAMUS
inferior-most portion of the diencephalon
lies within the floor and ventral part of the walls of the third ventricle
functions primarily in the maintenance of homeostasis
subserves three systems: the autonomic nervous system (ANS), the endocrine system, and the limbic system
It is divided into a series of regions, each of which contain a variety of nuclei
It is also divided into medial and lateral zones
SURFACE ANATOMY OF THE HYPOTHALAMUS
ventral surface structures :
Infundibulum
Tuber cinereum
median eminence arcuate nucleus
Mammillary bodies
Cerebral arterial circle
HYPOTHALAMIC REGIONS & NUCLEI
The hypothalamus is divided into a lateral area and a medial area separated by the fornix and the mammillothalamic tract
LATERAL AREA
traversed by the medial forebrain bundle
LATERAL PREOPTIC NUCLEUS
the anterior telencephalic portion
LATERAL HYPOTHALAMIC NUCLEUS
stimulation induces eating
destruction results in starvation anorexia
MEDIAL AREA
includes the periventricular area that borders the third ventricle
divided into four regions, from anterior to posterior :
PREOPTIC REGION - AREA
MEDIAL PREOPTIC NUCLEUS
Contains sexually dimorphic nucleus;
regulates release of gonadotropic hormones;
parasympathetic activity
SUPRAOPTIC REGION
SUPRACHIASMATIC NUCLEUS
receives direct input from the retina
Plays a role in circadian rhythms
ANTERIOR NUCLEUS
Involved in thermoregulation;
destruction causes hypothermia;
role in sleep regulation
stimulates parasympathetic NS
PARAVENTRICULAR NUCLEUS
Secretes oxytocin and vasopressin (magnocellular part);
secretes corticotropin-releasing hormone (parvocellular part)
SUPRAOPTIC NUCLEUS
Secretes oxytocin and vasopressin
PV & SO
regulate water balance
produce ADH and oxytocin
destruction causes diabetes insipidus
paraventricular nucleus projects to autonomic nuclei of brainstem and spinal cord
TUBERAL REGION OR MIDDLE
DORSOMEDIAL NUCLEUS
Plays a role in circadian rhythms, feeding, and emotions
stimulation results in obesity and savage behavior
VENTROMEDIAL NUCLEUS
Satiety center
destruction results in obesity and savage behavior
ARCUATE (INFUNDIBULAR) NUCLEUS
Secrete growth hormone–releasing hormone
produces hypothalamic-releasing factors
contains DOPA-ergic neurons that inhibit prolactin release
MAMMILLARY REGION POSTERIOR
MAMMILLARY NUCLEI
receives input from hippocampal formation via fornix
projects to anterior nucleus of thalamus
contains hemorrhagic lesions in Wernicke encephalopathy
Memory consolidation
POSTERIOR NUCLEUS
Heat conservation center, arousal, wakefulness
thermal regulation (conservation of heat)
destruction results in inability to thermoregulate
stimulates the sympathetic NS
MAJOR HYPOTHALAMIC CONNECTIONS
characterized by mostly reciprocal connections
AFFERENT CONNECTIONS TO THE HYPOTHALAMUS
Septal area and nuclei and orbitofrontal cortex
Hippocampal formation
Amygdaloid complex
Primary olfactory cortex (area 34)
Mediodorsal nucleus of the thalamus
Brainstem nuclei
Tegmental nuclei (dorsal and ventral)
Raphe nuclei (dorsal and superior central)
Locus ceruleus
EFFERENT CONNECTIONS TO THE HYPOTHALAMUS
Septal area and nuclei
Anterior nucleus of the thalamus
Mediodorsal nucleus of the thalamus
Amygdaloid complex
Brainstem nuclei and spinal cord
Adenohypophysis
Neurohypophysis
MAJOR FIBER SYSTEMS
FORNIX
alveus, fimbria, crus, body, and column
is the largest projection to the hypothalamus
It projects from the hippocampal formation to the mammillary nucleus, anterior nucleus of the thalamus, and septal area
The fornix then projects from the septal area to the hippocampal formation
MEDIAL FOREBRAIN BUNDLE
traverses the entire lateral hypothalamic area
It interconnects the orbitofrontal cortex, septal area, hypothalamus, and midbrain
MAMMILLOTHALAMIC TRACT
projects from the mammillary nuclei to the anterior nucleus of the thalamus (part of the Papez circuit)
MAMMILARY PEDUNCLE
conducts fibers from the dorsal and ventral tegmental nuclei and the raphe nuclei to the mammillary body
MAMMILLOTEGMENTAL TRACT
conducts fibers from the mammillary nuclei to the dorsal and ventral tegmental nuclei
STRIA TERMINALIS
is the major pathway from the amygdala.
It interconnects the septal area, hypothalamus, and amygdala
VENTRAL AMYGDALOFUGAL PATHWAY
interconnects the amygdaloid complex and the hypothalamus
SUPRAOPTICOHYPOPHYSIAL TRACT
conducts fibers
from the supraoptic and paraventricular nuclei to the neurohypophysis,
which is the release site for ADH and oxytocin
TUBEROHYPOPHYSIAL (TUBEROINFUNDIBULAR) TRACT
conducts fibers from the arcuate nucleus to the hypophyseal portal system
DORSAL LONGITUDINAL FASCICULUS
extends from the hypothalamus to the caudal medulla
projects to the parasympathetic nuclei of the brainstem
HYPOTHALAMOSPINAL TRACT
contains direct descending autonomic fibers
These fibers
influence the preganglionic sympathetic neurons of the
intermediolateral cell column and preganglionic neurons of the sacral
parasympathetic nucleus.
Interruption above the first thoracic segment (T-1) causes Horner syndrome.
FUNCTIONAL CONSIDERATIONS
AUTONOMIC FUNCTION
In
general terms, the ANTERIOR & medial aspects of the hypothalamus have
a more “parasympathetic” role,
and the POSTERIOR & lateral aspects
have a more “sympathetic” function
There exist functional centers in the hypothalamus :
TEMPERATURE REGULATION
Anterior hypothalamus lesion = Hyperthermia
Posterior hypothalamus lesion = Hypothermia
WATER BALANCE REGULATION
ADH controls water excretion by the kidneys
Lesion of the anterior hypothalamus = Diabetes insipidus
FOOD INTAKE REGULATION
Ventromedial nucleus lesion = Hyperphagia
Lateral hypothalamus lesion = Hypophagia hunger or feeding center starvation and emaciation
HYPOTHALAMIC-RELEASING & RELESEASE-INHIBITING HORMONES
arcuate nucleus with the exception of dopamine, they are all peptides :
Thyrotropin-releasing hormone
Gonadotropin-releasing hormone
Somatostatin (growth hormone—inhibiting hormone)
Growth hormone—releasing hormone
CRH
PIF and prolactin-releasing factor
SLEEP-WAKE CYCLE
Anterior hypothalamus lesion = Insomnia
Posterior hypothalamus lesion = Hypersomnia
EMOTIONS
lesion of the ventromedial nucleus = Rage
CLINICAL CORRELATIONS
DIABETES INSIPIDUS
SYNDROME OF INAPPROPRIATE ADH SECRETION
CRANIOPHARYNGIOMA
supratentorial tumor
pressure on the optic chiasm results in a bitemporal hemianopia
Pressure on the hypothalamus causes hypothalamic syndrome
PITUITARY ADENOMAS
pressure on the chiasm results in a bitemporal hemianopia
Pressure on the hypothalamus may cause hypothalamic syndrome
WERNICKE ENCEPHALOPATHY
Vitamin B1
ocular palsies, ataxic gait, and mental confusion
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VESTIBULOCOCHLEAR VIII
SSA
Vestibular and cochlear nerves join in the internal auditory meatus and enterthe brain stem in the cerebellopontine angle
vestibular nerve projects to the vestibular nuclei andthe flocculonodular lobe of the cerebellum
cochlear nerve projects to the cochlear nuclei
VESTIBULAR NERVE
GENERAL CHARACTERISTICS
Vestibular ganglion (internal auditory meatus)
Equilibrium (innervates hair cells of semicircular ducts, saccule, and utricle)
equilibrium and balance
compensatory eye movements
CLINICAL CORRELATIONS : LESIONS
disequilibrium, vertigo, and nystagmus
COCHLEAR NERVE
GENERAL CHARACTERISTICS
Spiral ganglion (modiolus of temporal bone)
Hearing (innervates hair cells of the organ of Corti)
CLINICAL CORRELATIONS : LESIONS
hearing loss
tinnitus
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AUDITORY SYSTEM
The auditory and vestibular systems consist of morphologically and functionally interconnected structures
Both are housed
in the inner ear deep in the temporal bone, both send axons centrally
that travel in the vestibulocochlear nerve (CN VIII), and disruptions
of one system often affect the other
INTRODUCTION
Three features of sounds we perceive:
1. Location: A central nervous system (CNS) comparison mediated by the superior olivary nucleus
2. Frequency: Determined by where along basilar membrane vibration is greatest
3. Amplitude: Determined by the number of hair cells that are stimulated and thereby the number of afferent nerve fibers that are firing
OUTER, MIDDLE, AND INNER EAR
The auditory system deals with the sense of hearing
The hearing apparatus is divided into an outer, middle, and inner ear
OUTER
Consists of the auricle and external auditory meatus
Extends medially to tympanic membrane, which vibrates when sound vibrations contact it
Funnels sound from outside world to tympanic membrane
Sensory innervation by CNs V, VII, and X
Functions in sound localization
MIDDLE - TYMPANIC CAVITY
chorda tympani CN VII
Tympanic membrane
Middle ear ossicles
malleus, incus, and stapes
Tensor tympani & stapedius
Auditory tube
Movement
of tympanic membrane causes the ossicles to vibrate in turn to transmit
vibration to oval window, which leads to inner ear
Sensory innervation by CN IX
Muscles dampen sound; auditory tube equalizes pressure with atmospheric
INNER - MEMBRANOUS LABYRINTH
bony labyrinth
cochlea
Consists of receptor organs within the cochlear duct of the membranous labyrinth
Vibrations originating at oval window stimulate hair cells in cochlear duct; part of the Organ of Corti
Vibration of the
footplate of the stapes in the oval window results in vibration of the
basilar membrane, upon which the Organ of Corti sits;
the Organ of Corti is composed of receptor cells called hair cells
Hair cells transduce vibrations into a neural signal, which is carried centrally by CN VIII
Scala vestibuli
perilymph
helicotrema, scala tympani, and round window
Cochlear duct (scala media)
endolymph
Organ of Corti
Hair cells
stereocilia
Basilar membrane
Spiral ganglion (of CN VIII)
bony modiolus
AUDITORY PATHWAY
The auditory pathway begins with the hair cells of the organ of Corti and ends in the primary auditory cortex
HAIR CELLS OF THE ORGAN OF CORTI
Inner and outer hair cells are stimulated by movement of endolymph in the cochlear duct and movement of the basilar membrane
Bending of the hair cells causes depolarization, which stimulates the first-order afferents of CN VIII
Inner hair cells
Outer hair cells
BIPOLAR CELLS OF THE SPIRAL (COCHLEAR) GANGLION
cochlear nerve
COCHLEAR NERVE (CRANIAL NERVE [CN] VIII)
Contains primary afferent fibers of auditory system
Cell bodies located in spiral ganglion located along the bony modiolus
Transmits impulses from cochlear duct to cochlear nuclei of the brainstem
COCHLEAR NUCLEI
Located in the medulla
Receive input from CN VIII
Divided into a dorsal and ventral group
Ventral
nuclei project bilaterally to superior olivary nucleus and through
lateral lemniscus to contralateral inferior colliculus
Dorsal nuclei project contralaterally to inferior colliculi via the acoustic stria
Crossing fibers form the trapezoid body
Dorsal cochlear nucleus
Ventral cochlear nucleus
SUPERIOR OLIVARY NUCLEUS
Located in the pons
Conveys information bilaterally to inferior colliculi
Fibers travel in lateral lemniscus
Receives input from ventral cochlear nuclei
Projects bilaterally
Involved in sound localization by making a temporal comparison of information coming from each ear
TRAPEZOID BODY
LATERAL LEMNISCUS
NUCLEUS OF INFERIOR COLLICULUS
brachium of the inferior colliculus
Located in midbrain tectum
Receives input from dorsal and ventral cochlear nuclei
Sends impulses to medial geniculate nucleus of thalamus
Fibers cross midline via commissure of inferior colliculus;
projects to superior colliculus to mediate audiovisual reflexes
MEDIAL GENICULATE BODY
(auditory radiation)
Part of thalamus
Receives projections from inferior colliculus
Projects to auditory cortex via sublenticular part of internal capsule, the auditory radiations
PRIMARY AUDITORY CORTEX (TRANSVERSE TEMPORAL GYRI OF HESCHL)
Located along superior temporal gyrus:
Brodmann’s areas 41 and 42, known as the transverse gyrus of Heschl
Tonotopic organization: Lower frequencies more anterior, higher frequencies more posterior
Input from medial geniculate nucleus
Projects to auditory association cortex: Area 22
Responsible for sound discrimination
Because
the cochlear nuclei project bilaterally, to get deafness in one ear,
the problem must occur at or proximal to the cochlear nuclei
(i.e., organ of Corti, spiral ganglion, or CN VIII)
EFFERENT COCHLEAR (OLIVOCOCHLEAR) BUNDLE
a crossed and uncrossed tract that arises from the superior olivary nucleus and projects to the hair cells of the organ of Corti
suppresses auditory nerve activity when stimulated
plays a role, through inhibition, in “auditory sharpening"
HEARING DEFECTS
CONDUCTION DEAFNESS
Conduction deafness results when any part of the external or middle ear is damaged in such a way as to impede transfer of sound vibrations to the inner ear
Obstruction by wax (cerumen) or by a foreign body
Otosclerosis
Otitis media
inflammation of the middle ear
NERVE DEAFNESS (SENSORINEURAL, OR PERCEPTIVE, DEAFNESS)
Nerve deafness results from damage to the cochlea, CN VIII, or central auditory pathway
disease
action of drugs and toxins
prolonged exposure to loud noise
rubella infection in utero
Presbycusis
hearing loss occurring with aging
Acoustic neuroma
unilateral deafness and tinnitus
AUDITORY TESTS
TUNING FORK TESTS
WEBER TEST
RINNE TEST
SCHWABACH TEST
BRAINSTEM AUDITORY EVOKED RESPONSE (BAER)
Testing method
Diagnostic value
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VESTIBULAR SYSTEM
INTRODUCTION
involved with the sense of equilibrium and balance
semicircular canals are involved in detection of angular or changing movement,
whereas the macular organs are involved with perceiving static position
coordinates head and eye movements
LABYRINTH
(auris interna)
STRUCTURE
Bony labyrinth
perilymph
Membranous labyrinth
endolymph
FUNCTION
SEMICIRCULAR CANALS - KINETIC
respond to angular acceleration & deceleration of the head
three semicircular canals
Hair cells
respond to endolymph flow
UTRICLE & SACCULE - STATIC
linear acceleration & gravity
head tilt/position
Maculae of the utricle & saccule ("otolith organs")
Hair cells
otolithic membrane
FLUIDS OF THE LABYRINTH
Perilymph
Endolymph
stria vascularis
VESTIBULAR PATHWAYS
HAIR CELLS OF THE SEMICIRCULAR DUCTS, SACCULE, AND UTRICLE
SEMICIRCULAR CANALS
Contain receptors for detection of angular acceleration of the head
Cristae ampullari located in the semicircular canals detect head movement by endolymph deformation of hair cells embedded in the gelatinous cupula
Deformation
of the cilia of the hair cells stimulates the primary afferents of CN
VIII, the cell bodies of which are located in the vestibular (Scarpa’s)
ganglion
MACULAR ORGANS: UTRICLE AND SACCULE
Contain receptors for linear acceleration; constant
Saccule responds maximally when head is vertical
Utricle responds maximally when head is perpendicular to body
Detects position by maculae; contains otoliths within gelatinous membrane into which cilia of hair cells are embedded
Otoliths
make the gelatinous membrane “heavy,” such that it responds to gravity
and does not allow the gelatinous membrane to reset to resting position
until head is repositioned
Deformation
of the cilia of the hair cells stimulates the primary afferents of CN
VIII, the cell bodies of which are located in the vestibular (Scarpa’s)
ganglion
BIPOLAR NEURONS OF THE VESTIBULAR GANGLION
internal auditory meatus
Contains primary afferent cell bodies of CN VIII
Projects centrally to vestibular nuclei of brainstem
Projects to cerebellum via juxtarestiform body to the flocculonodular lobe
VESTIBULAR NUCLEI
Located in pons and rostral medulla on floor of fourth ventricle
Divided into superior, inferior, medial and lateral nuclear groups
RECEIVE INPUT FROM THE FOLLOWING STRUCTURES
Bipolar neurons of the vestibular ganglion - semicircular ducts, saccule, and utricle
Flocculonodular lobe and uvula of the cerebellum
Vermis of the anterior lobe of the cerebellum
Vestibular nuclei of the contralateral side
Fastigial nuclei of the cerebellum
PROJECT FIBERS TO THE FOLLOWING STRUCTURES
oculomotor, abducens, and trochlear nuclei via medial longitudinal fasciculus
Flocculonodular lobe and uvula of the cerebellum
Vestibular nuclei of the contralateral side
Inferior olivary nucleus
receives input via the vestibulo-olivary tract
mediates vestibular influence to the vermis of the cerebellum
Abducens, trochlear, and oculomotor nuclei
receive input via the medial longitudinal fasciculus (MLF)
Anterior horn motor neurons - receive vestibular input from two descending pathways :
MLF
contains fibers from the medial vestibular nucleus that terminate in cervical and upper thoracic levels.
coordinates head, neck, and eye movements
Vestibulospinal tract
contains fibers from the ipsilateral lateral vestibular nucleus and is found at all spinal cord levels
facilitates extensor muscle tone in the antigravity muscles, thus maintaining upright posture
Ventral posterior nuclei of the thalamus
receive bilateral input from the vestibular nuclei
FUNCTION
Fibers to CN III, IV, and VI nuclei coordinate head and eye movement and mediate vestibulo-ocular reflex
Fibers synapse at cervical levels of spinal cord via medial vestibulospinal tract to control head and neck musculature
Fibers descend the length of the spinal cord via the lateral vestibulospinal tract to control balance and extensor tone
Project
to cerebellum, contralateral vestibular nuclei, inferior olivary
nuclei, and thalamus (ventral posterior inferior and ventral posterior
lateral); project to primary vestibular cortex (area 2) and parietal
lobe
VENTRAL POSTERIOR NUCLEI OF THE THALAMUS
project to the primary vestibular cortex of the parietal lobe
EFFERENT VESTIBULAR CONNECTIONS
arise from neurons in the vestibular nuclei
exit the
brainstem with the vestibular nerve and innervate hair cells in the
cristae ampullari and maculae of the utricle and saccule
modulate the firing rate ofvestibular nerve fibers
activation reduces motion sickness
MEDIAL LONGITUDINAL FASCICULUS
extends from the spinal cord to the rostral midbrain
contains ascending vestibulo-ocular fibers to the motor nuclei of CNs III, IV, and VI
contains a descending medial vestibulospinal tract that coordinates head and eye movements
mediates adduction of the eyeball in lateral conjugate gaze
mediates vestibular nystagmus
transection results in medial rectus palsy on attempted lateral gaze
VESTIBULO—OCULAR REFLEXES
consist of reflex movement of the eyes to compensate for head movement to keep objects of interest on the center of the retina
can be tested in conscious or unconscious subjects by stimulating the semicircular canal system
afferent limb is CN III
efferent limb is CNs III, IV, and VI
The
eyes move slowly opposite the direction of head movement, thus keeping
the object of interest centered on the fovea centralis
OCULOCEPHALIC REFLEX (DOLL'S HEAD EYES MOVEMENT)
Test method
Test results
VESTIBULAR (HORIZONTAL) NYSTAGMUS
fast phase of nystagmus is in the direction of rotation
slow phase of nystagmus is in the opposite direction
POSTROTATORY (HORIZONTAL) NYSTAGMUS
Test method
Test results
CALORIC NYSTAGMUS (STIMULATION OF HORIZONTAL DUCTS)
Test method (used to stimulate the horizontal semicircular canal)
Test results
COWS = Cold, Opposite; Warm, Same
Test results (in comatose subjects)
TEST RESULTS IN UNCONSCIOUS SUBJECTS
CLINICAL CORRELATIONS
VERTIGO
illusion of movement
MENIERE DISEASE
increase in endolymphatic fluid pressure
LABYRINTHITIS
inflammation of the labyrinth
LABYRINTHECTOMY
Unilateral labyrinthectomy
Bilateral simultaneous labyrinthectomy
BENIGN POSITIONAL VERTIGO
cuprolithiasis
INTERNUCLEAR OPHTHALMOPLEGIA INO
multiple sclerosis
ACUSTIC SCHWANOMMA VESTIBULAR
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VISUAL SYSTEM
GENERAL CHARACTERISTICS OF CN II
SSA
Retinal ganglion cells
Vision and pupillary light reflexes
Central axons converge at the optic
disk and form the optic nerve, which
enters the skull via the optic canal
Optic nerve axons terminate primarily
in the lateral geniculate bodies
not a true peripheral nerve
CLINICAL CORRELATIONS : CN II
ipsilateral blindness and loss of direct pupillary light reflex
papilledema
optic atrophy
The visual system is responsible for processing images formed from light hitting the retina
It is composed of neural relay systems that begin in the eye, travel in the optic nerve and tract to the lateral geniculate nucleus (LGN) of the thalamus and finally to the visual cortex
INTRODUCTION
STRUCTURES
EYE
Description
Composed of three layers (tunics):
1. Outer: Sclera and cornea
2. Middle: Choroid, iris, and ciliary body
3. Inner: Retina
Connections
Retina is composed of seven layers
Impulses are conducted from superficial to deep
Function
Structure of the eye focuses light on the retina, particularly the center
Impulses from photoreceptors sent to ganglion cells, which form the optic nerve
RETINA
STRUCTURES OF THE OCULAR FUNDUS - RETINAL PART OPPOSITE TO THE PUPIL
Optic disk (optic papilla)
Medial to fovea, blind spot; contains axons from ganglion cells
Macula lutea
Yellow pigmented area surrounding fovea centralis
Fovea centralis
area of highest visual acuity; contains cones only
Retinal blood supply
choriocapillaris - central retinal artery
CELLS OF THE RETINA Composed of five cell types, from superficial to deep :
1) Rods and cones - Photoreceptors
Rods (100 million) - rhodopsin
Cones (7 million) - iodopsin
2) Bipolar neurons
5) Ganglion cells
lnterneurons
3) Horizontal cells
4) Amacrine cells
Muller cells
Connections
Photoreceptors are stimulated, sending an impulse that eventually stimulates ganglion cells that form the optic nerve
Function
Receives focused images from the cornea and lens, which initiates an impulse that is transmitted to the optic nerve
The seven-layered inner tunic of the eye develops as an outgrowth of the diencephalon; it has five cell types within it .
The seven layers of the retina from superficial to deep are :
Retinal pigmented epithelium
Photoreceptor layer
Outer nuclear layer
Outer plexiform layer
Inner nuclear layer
Inner plexiform layer
Ganglion cell layer
Cell types
Description
Connections
Function
PHOTORECEPTOR
Two types: Rods and cones
Consist of cell body and synaptic terminal; respond to light
Glutamate is the neurotransmitter
Synapse on bipolar and horizontal cells
Rods: Provide low-acuity images; monochromatic
Cones: Provide images with high visual acuity; color vision; need a lot of light
Both convert stimulation from light into neuronal impulses
BIPOLAR
Receive impulse from photoreceptors
Located between inner and outer plexiform layer
Glutamate is the neurotransmitter
Terminate on ganglion cells
Provide pathway from photoreceptors to ganglion cells
AMACRINE
Located between inner nuclear layer and outer plexiform layer
γ-Aminobutyric acid (GABA), dopamine, and acetylcholine act as neurotransmitters
Synapse on ganglion cells in the outer plexiform layer
Inhibit ganglion cells
HORIZONTAL
Located in the nuclear and plexiform layers
GABA is the neurotransmitter
Synapse on bipolar cells
Modify the responses of the bipolar cells
Role in color differentiation
Responsible for lateral inhibition of photoreceptors
GANGLION
Only source of output from retina, act as third-order afferents
Glutamate is the neurotransmitter
Axons leave retina as optic nerve (CN II)
Axons continue to optic chiasm as optic nerve
Influenced by bipolar and horizontal cells
The ganglion cells form the optic nerve (CN II); they project to the:
Thalamus (LGN)
Superior colliculus : To mediate visual reflexes and for dynamic visual map of environment
Hypothalamus (suprachiasmatic nucleus) : To mediate circadian rhythms
Pretectal nucleus : Role in
mediating behavioral responses to light: pupillary light reflex,
optokinetic reflex, accommodation reflex, and circadian rhythms.
Lateral inhibition is the property of an activated neuron to inhibit
excitation of nearby neurons, thereby providing increased
discrimination of the excited neuron
MERIDIONAL DIVISIONS OF THE RETINA
monocular field - binocular field
nasal - temporal hemiretinae
Temporal hemiretina
Nasal hemiretina
Upper retinal quadrants
Lower retinal quadrants
CONCENTRIC DIVISIONS OF THE RETINA & RETINOTOPY
Macular area
Paramacular area
Monocular area
PATHWAYS
VISUAL PATHWAY
The visual image is transferred from the retina to the cerebral cortex by the central visual pathway
Along the way, the image is distributed to various parts of the central nervous system (CNS)
Description
Connections
GANGLION CELLS OF THE RETINA
OPTIC NERVE
not a true nerve Actually a myelinated tract of the diencephalon
Invested with arachnoid, pia, and subarachnoid space
optic atrophy
Ganglion cell axons exit the eye at the optic disk and travel to the optic chiasm
Transmit impulses from retina to optic chiasm
Transection
ipsilateral blindness
Lesion
junction scotoma
OPTIC CHIASM
Impulses from nasal retina cross midline to join impulses from temporal retina of contralateral eye;
thus, visual
information from the left visual field of both eyes travels down the
right side of the visual pathway and vice versa
Located immediately superior to hypophysis
Receives input from CN II;
nasal retinal fibers cross and leave posteriorly as optic tract
Midsagittal transection or pressure
heteronymous bitemporal hemianopia
Bilateral lateral compression
heteronymous binasal hemianopia
OPTIC TRACT
Conveys matched visual field information from each eye posteriorly;
has fibers from the ipsilateral temporal hemiretina and contralateral nasal hemiretina
Connects the optic chiasm to the LGN of the thalamus
contralateral homonymous hemianopia
LATERAL GENICULATE BODY
Part of the posterior aspect of the thalamus
Composed of six layers, separated by the visual field to which they are related:
Ipsilateral temporal hemiretina (layers 2, 3, and 5)
Contralateral nasal hemiretina (layers 1, 4, and 6)
And/or identified by cell size:
Magnocellular layers (layers 1 and 2): Responsible for relaying contrast and movement information
Parvocellular layers (layers 3–6): Responsible for relaying color and form information
Fibers travel to the occipital lobe as the geniculocalcarine tract or optic radiations
Inferior visual
field fibers terminate on the superior bank of the calcarine sulcus,
superior visual field fibers terminate on the inferior bank of the
calcarine sulcus
contralateral homonymous hemianopia
GENICULOCALCARINE TRACT (VISUAL RADIATION, RETROLENTICULAR PART OF CI) - OPTIC RADIATIONS
Fan out as the retrolenticular part of the internal capsule
Fibers extending inferomedially into the temporal lobe are known as Meyer’s loop
Transmit impulses from LGN to primary occipital cortex
Left optic radiations carry all information from right visual fields of both eyes and vice versa
contralateral homonymous hemianopia
Upper division
cuneus
Transection - contralateral lower homonymous quadrantanopia
Lesions
Lower division
lingual gyrus
Transection - contralateral upper homonymous quadrantanopia
Transection - upper altitudinal hemianopia (altitudinopia)
PRIMARY VISUAL CORTEX (BRODMANN AREA 17)
Cortical area (17) along the calcarine sulcus of the occipital lobe
Visual information is inverted and reversed upon reaching area 17
Information from the inferior visual fields terminates superior to the calcarine sulcus on the cuneate gyrus;
information from superior visual fields terminates inferior to the calcarine sulcus on the lingual gyrus
Primary visual cortex sorts and sends information to other cortical areas: Visual association cortices (18 and 19)
cuneus
lingual gyrus
macular sparing
contralateral homonymous hemianopia - lower altitudinal hemianopia - upper altitudinal hemianopia
Possesses retinotopic organization
Central part of retina is represented most posteriorly and occupies a disproportionately large amount of the visual cortex
More peripheral parts are represented more anteriorly
Posterior third of the visual cortex
Intermediate area of the visual cortex
Anterior area of the visual cortex
Because the optic nerve is a tract of the diencephalon, it is not actually a nerve
A retinotopic organization is maintained from the retina all of the way to the primary visual cortex
The word SLIM can help you remember the relationship between elements of the visual system:
The Superior Colliculus receives input from the Lateral Geniculate Nucleus
The Inferior Colliculus receives input from the Medial Geniculate Nucleus
PUPILLARY LIGHT REFLEXES & PATHWAY
PUPILLARY LIGHT REFLEXES
Direct pupillary light reflex
Consensual pupillary light reflex
PUPILLARY LIGHT REFLEX PATHWAY
CN II - CN III
Ganglion cells of retina
Pretectal nucleus of midbrain
Accessory oculomotor nucleus of III
Ciliary ganglion
PUPILLARY DILATION PATHWAY
Horner syndrome
HYPOTHALAMUS
CILIOSPINAL CENTER (OF BUDGE)
SUPERIOR CERVICAL GANGLION
tympanic cavity and cavernous sinus and enter the orbit through the superior orbital fissure
THE CONVERGENCE—ACCOMMODATION REACTION - THE NEAR REFLEX & ACCOMMODATION PATHWAY
REFLEX CHANGES
Convergence
Accommodation
Pupillary constriction
CONVERGENCE—ACCOMMODATION PATHWAY
Visual cortex (area 17) cortical visual pathway
Visual association cortex (area 19)
Pretectal area - superior colliculus and pretectal nucleus - oculomotor complex
rostral accessory oculomotor (Edinger–Westphal) nucleus
caudal accessory oculomotor (Edinger–Westphal) nucleus
Convergence nucleus (of Perlia)
CENTERS FOR OCULAR MOTILITY
FRONTAL EYE FIELD
Stimulation - contralateral coniugate deviation of the eyes
Destruction - transient ipsilateral coniugate deviation of the eyes
OCCIPITAL EYE FIELDS AREAS 18 AND 19
Stimulation - contralateral coniugate deviation of the eyes
SUBCORTICAL CENTER FOR LATERAL CONJUGATE GAZE
rostral interstitial nucleus of the medial longitudinal fasciculus (MLF)
Parinaud syndrome
SUBCORTICAL CENTER FOR VERTICAL CONJUGATE GAZE
medial rectus palsy
VISUAL PROCESSING
Visual processing involves fast and slow conjugate eye movements
Saccades are fast, steplike movements that bring objects onto the retina
The velocity of
a saccadic eye movement is too fast for the visual system to relay the
information it receives, so the CNS computes the size of the movement in advance and initiates it reflexively
Smooth, slow tracking movements allow images to stay on the fovea centralis
SACCADIC MOVEMENTS
Fast, steplike movements
Initiated by the frontal eye fields: part of the prefrontal cortex and the superior colliculus
Bring objects of interest onto retina
Velocity too
great for visual system, so CNS computes size of movement in advance
and suppresses perception of vision during movement
SLOW PURSUIT MOVEMENTS
Slow, cortically driven tracking
Allows images to stay on the fovea centralis
VISUAL ASSOCIATION CORTEX
Brodmann’s areas 18, 19, 20, and 37
Provides meaning associated with vision
Projects “where” information to parieto-occipital cortex and projects “what” information to occipitotemporal cortex
Separates complex visual information into two “streams”
Dorsal: Where
Ventral: What
Nystagmus is the combined action of a fast saccadic eye movement in one direction and a slow pursuit movement in the opposite direction,
which is necessary to keep objects of interest focused on the retina
CLINICAL CORRELATIONS
ANISOCORIA (UNEQUAL PUPILS)
Horner syndrome - third nerve palsies
MLF SYNDROME, OR INTERNUCLEAR OPHTHALMOPLEGIA INO
medial rectus palsy on attempted lateral conjugate gaze - Convergence is normal - monocular horizontal nystagmus - multiple sclerosis
ONE-AND-A-HALF SYNDROME
ARGYLL ROBERTSON PUPIL (PUPILLARY LIGHT–NEAR DISSOCIATION)
syphilis, diabetes mellitus, and lupus erythematosus
AFFERENT (MARCUS GUNN) PUPIL
lesion in the afferent limb of the pupillary light reflex - retrobulbar neuritis - multiple sclerosis
swinging flashlight test
pupillary constriction
dilation of the afferent pupil
TRANSTENTORIAL (UNCAL) HERNIATION
increased supratentorial pressure
ipsilateral hemiparesis
a fixed and dilated pupil, ptosis, and a down-and-out eye
contralateral homonymous hemianopia
PAPILLEDEMA (CHOKED DISK)
The optic nerve is part of the diencephalon and as such is invested with arachnoid, pia, and subarachnoid space;
increases in intercranial pressure compress the nerve, leading to papilledema (swelling of the optic disk)
does not alter visual acuity - enlarged blind spots
brain tumors, subdural hematoma, and hydrocephalus
ADIE (HOLMES-ADIE) PUPIL
PTOSIS
Oculomotor ptosis
Oculosympathetic ptosis
Myasthenic ptosis
VISUAL DEFICITS
Visual deficits are named for visual field loss, not retinal loss
The optic chiasm
lies immediately superior to the pituitary gland; thus, a pituitary
tumor may put pressure on the fibers running through the chiasm
Whereas
midsagittal pressure results in bitemporal hemianopia, bilateral
compression from calcification of the internal carotid arteries in the
cavernous sinus may result in binasal hemianopia
TOC
OLFACTORY, GUSTATORY & LIMBIC SYSTEMS
TOC
OLFACTORY SYSTEM
GENERAL CHARACTERISTICS OF CN I
SVA
Bipolar olfactory neurons (in olfactory
epithelium in roof of
nasal cavity)
Smell (olfaction)
Central axons project to the
olfactory bulb via the cribriform
plate of the ethmoid bone
CLINICAL CORRELATION : CN I DAMAGE
anosmia
Olfaction is a phylogenetically old sense
Various chemicals and chemical concentrations dissolved in the nasal
mucosa stimulate an array of olfactory receptors, which are interpreted
by the olfactory cortex to create the sense of smell
Our ability to detect the huge range of odors that we are capable of is still poorly understood
OLFACTORY PATHWAY
MICROANATOMY
Epithelium = glands + mucosa - Sustentacular cell - Tufted cells
OLFACTORY NERVE = R + Bulb (glomeruli + mitral C) + Tract + Trigone
OLFACTORY RECEPTOR CELLS (FILA OLFACTORIA) - OLFACTORY EPITHELIUM
mitral - tufted cells
Three cell types:
Basal : Stem cells; give rise to olfactory receptor neurons
Supporting : Secrete granules onto mucosal surface
Receptor : First-order, bipolar neurons capable of mitosis; cilia provide transduction surface for odor stimulants
The olfactory receptor cells (neurons) are some of the only neurons in the human nervous system that are capable of mitosis
Signals are transmitted from the olfactory epithelium to the olfactory bulb by passing through the cribriform plate of the ethmoid
the fibers passing through the cribriform plate collectively form the olfactory nerve (CN I)
OLFACTORY BULB
Site of second-order neurons: Mitral cells & Tufted cells
Located on the cribriform plate of the ethmoid
Receives input from the olfactory nerve
Conducts impulse from olfactory neurons to olfactory cortex via the olfactory tract and lateral olfactory stria
Allows a specific response to stimulants through selective stimulation of receptors and second-order neurons
OLFACTORY TRACT
Contains anterior olfactory nucleus
Divides into lateral and medial olfactory stria
Anterior olfactory nucleus regulates and modulates the distribution of olfactory information
LATERAL OLFACTORY STRIA
Piriform
cortex - EC-hippocampus system (Entorhinal cortex Hippocampal
formation) - Prepyriform area - Periamygdaloid cortex
Stria medullaris → Habenular nuclei
Amygdala → Stria terminalis → Hypothalamus
Medial forebrain bundle → Hypothalamus
PRIMARY OLFACTORY CORTEX
prepiriform - periamygdaloid cortices
Site of the third-order neuron
Overlies uncus, part of the prepiriform and entorhinal cortices
Possesses a direct cortical projection (bypasses the thalamus)
Sends impulses to the dorsomedial nucleus of thalamus, basal forebrain, and limbic system
Allows
for specific perception of odor through connections with limbic system
: Emotional response and memory formation and retrieval related to odor
DORSOMEDIAL NUCLEUS OF THE THALAMUS
CLINICAL CORRELATIONS
Anosmia
Fracture of the thin cribriform plate that damages the olfactory receptor cells is a common cause of anosmia (loss of smell).
Puncture or tear of the dura mater is common, causing cerebrospinal fluid to leak from the nasal cavity.
Smell returns after regeneration of the receptor cells
fractures of the cribriform plate - meningitis, meningiomas, or gliomas
Olfactory hallucinations
Foster Kennedy syndrome
meningioma of the olfactory groove
Fracture of the cribriform plate of the ethmoid bone
TOC
GUSTATORY SYSTEM
Taste is perceived through stimulation of the taste buds
Flavor is taste plus olfactory, somatosensory, visual, and limbic input
Mood, proximity to the previous meal, temperature, smell, and the appearance and feel of food all affect flavor
GUSTATORY PATHWAY
TASTE (GUSTATORY) RECEPTOR CELLS
Located within taste buds of the tongue and oral cavity
Cilia extend through taste pore
Modified epithelial cells with neuron-like properties
Replaced every 1–2 weeks
Depolarized gustatory cell synapses with first-order neuron whose dendrites wrap the cell
Cilia project through pore and are bathed by saliva; chemicals cause the cells to depolarize
Five tastants: Sweet, sour, bitter, salty, and umami (savory)
FIRST-ORDER NEURON
Pseudounipolar cells located in the geniculate (CN VII), petrosal (CN IX), and nodose (CN X) ganglia
Forms afferent limb of reflex: Coughing, swallowing
Carried on processes of CNs VII, IX, and X
CNs convey impulses from tongue to nucleus solitarius via the solitary tract
Anterior 2/3 of tongue: CN VII
Posterior 1/3 of tongue: CN IX
Epiglottis, soft palate: CN X
Relays neural information from tongue to nucleus solitarius
SOLITARY NUCLEUS - SECOND ORDER NEURON
Located in medulla in the gustatory portion (rostral-most) of nucleus solitarius : the gustatory nucleus
Receives input from CNs
Fibers pass ipsilaterally via the central tegmental tract to the medial-most part of the ventral posteromedial (VPM) nucleus of the thalamus
Projects to parabrachial nucleus of pons
Second-order neurons of the nucleus solitarius receive and combine taste information from all three CNs carrying taste
Parabrachial nucleus passes taste information to the hypothalamus and amygdala
PARABRACHIAL NUCLEUS OF THE PONS
VPM NUCLEUS - THIRD ORDER NEURON
Located in the medial-most part of the VPM of the thalamus
Receive input from nucleus solitarius
Conveys taste information to cortex via internal capsule
Conveys ipsilateral taste information from VPM to gustatory cortex
GUSTATORY CORTEX OF THE INSULAR AREA (AREA 43)
Brodmann’s area 36
Located near insula and medial surface of frontal operculum near the base of the central sulcus
Receives input from VPM
Projects to orbital cortex of frontal lobe and to the amygdala
Integrates taste information with other areas (limbic, olfactory, visual, and sensory systems) to produce perceptionof flavor
TASTE PERCEPTION
The most commonly recognized tastes of the taste buds
sweetness
saltiness
bitterness
sourness
FLAVOR PERCEPTION
CLINICAL CORRELATION : AGEUSIA (GUSTATORY ANESTHESIA OR LACK OF SENSE OF TASTE)
Smoking is the most common cause of ageusia (loss of taste)
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CEREBRUM TELENCEPHALON
(Kamina)
V1 PDF
TOC
LIMBIC SYSTEM
The limbic system is a collection of structures deep in the brain that are collectively involved in emotional memory, behavior, and memory consolidation
The limbic system activities are expressed through the hypothalamus
The structures of the limbic system may be grouped into
MEDIAL & BASAL FOREBRAIN = SEPTAL AREA + VENTRAL FOREBRAIN
MEDIAL TEMPORAL LOBE = HIPPOCAMPAL FORMATION & UNCUS = HIPPOCAMPUS (PART OF HF) + DENTATE GYRUS (PART OF HF)
LIMBIC LOBE = CINGULATE GYRUS + PARAHIPPOCAMPAL GYRUS + AMYGDALA
MAJOR COMPONENTS & CONNECTIONS
ORBITOFRONTAL CORTEX
smell
DORSOMEDIAL NUCLEUS OF THE THALAMUS
affective behavior - memory
ANTERIOR NUCLEUS OF THE THALAMUS
circuit of Papez
SEPTAL AREA
stria medullaris (thalami) - habenular nucleus
Located close to the midline and inferior to the corpus callosum on the medial aspect of the frontal lobe
Connections:
Hippocampal formation via the fornix
Hypothalamus via the medial forebrain bundle
Habenula via the stria medullaris
Cerebral cortex via diffuse projections
Involved in the regulation of appropriate attention to stimuli and of motivation, stimulation results in feelings of pleasure
VENTRAL FOREBRAIN
General region at base of frontal lobe deep to septal area cortex and below anterior commissure
Connections :
Cerebral cortex
Thalamus
Substantia nigra
Cingulate gyrus
Limbic system
Parahippocampal gyrus
Regulates body posture & muscle tone that accompany behavior and emotional states, such as fear, stress, and pleasure
LIMBIC LOBE
subcallosal area - paraterminal gyrus - cingulate gyrus - isthmus - parahippocampal gyrus - uncus
hippocampal formation - amygdaloid nuclear complex
Memory formation and emotional response to stimuli; regulation of visceral responses that accompany behavior
CINGULATE GYRUS
Long, arching gyrus superior to the corpus callosum
Connections :
Cerebral cortex
Thalamus
Mammillary bodies
Hypothalamus
Hippocampal formation
Septal area
Amygdala
Brainstem
PARAHIPPOCAMPAL GYRUS
Parallels and lies deep to hippocampus
Continuous posteriorly with the cingulate gyrus
Major component is entorhinal cortex
Connections :
Cerebral cortex
Hippocampal formation
MEDIAL TEMPORAL LOBE = HIPPOCAMPAL FORMATION & UNCUS
Functions in learning and memory, short-term memory consolidation into long-term memory, and recognition of novelty
HIPPOCAMPAL FORMATION
MAJOR STRUCTURES OF THE HIPPOCAMPAL FORMATION
DENTATE GYRUS granule cells
Located within temporal lobe
Connections :
Hippocampus
Entorhinal cortex via fornix
HIPPOCAMPUS (cornu ammonis) pyramidal cells
Located along medial aspect of cerebrum; borders the inferior horn of the lateral ventricle within the temporal lobe
Connections :
Septal area via fornix
Hypothalamus (including mammillary bodies) via fornix
Dentate gyrus
Subiculum
Parahippocampal gyrus
SUBICULUM
MAJOR AFFERENT CONNECTIONS TO THE HIPPOCAMPAL FORMATION
cerebral association cortices
septal area
anterior nucleus of the thalamus
MAJOR EFFERENT CONNECTIONS FROM THE HIPPOCAMPAL FORMATION
mammillary nucleus of the hypothalamus
septal area.
anterior nucleus of the thalamus
AMYGDALA
Located within antero-medial aspect of temporal lobe, deep to the uncus
Connections :
Temporal and prefrontal cerebral cortex
Thalamus
Hypothalamus
Septal area
Corpus striatum
Brainstem
Regulates level of aggression in behavioral and emotional states, stimulation results in rage and anxiety
Receives typical
sensory input: somato- sensory, sight, smell, visceral sensation,
auditory and also receives sensory input on level of comfort or anxiety
(from cortical sources)
MAJOR AFFERENT CONNECTIONS TO THE AMYGDALA - FROM
olfactory bulb and olfactory cortex
cerebral cortex
hypothalamus
MAJOR EFFERENT CONNECTIONS FROM THE AMYGDALA - TO
cerebral cortex
hypothalamus
brainstem and spinal cord
HYPOTHALAMUS
LIMBIC MIDBRAIN NUCLEI
ventral tegmental area
raphe nuclei of the midbrain
locus ceruleus
MAJOR LIMBIC FIBER SYSTEMS
FORNIX
STRIA TERMINALIS
VENTRAL AMYGDALOFUGAL PATHWAY
STRIA MEDULLARIS (THALAMI)
DIAGONAL BAND OF BROCA
HABENULOINTERPEDUNCULAR TRACT—TRACTUS RETROFLEXUS
PAPEZ CIRCUIT
The Papez circuit is the first pathway described involving the limbic system properly
It includes the
cingulate gyrus to the hippocampal formation to the hypothalamus
(mammillary bodies) to the anterior nucleus of the thalamus back to the
cingulate gyrus
HIPPOCAMPAL FORMATION
fornix
MAMMILLARY BODY
mammillothalamic tract
ANTERIOR NUCLEUS OF THE THALAMUS
cingulate gyrus
CINGULATE GYRUS
Projections from the amygdala and hipppocampus to the striatum influence motor activity as it relates to mood and emotion
Whereas
stimulation of the amygdala causes stress and anxiety, stimulation of
the septal area causes pleasure and relaxation; these two systems
balance control of emotional responses depending on circumstances
The limbic system consolidates memory by long-term potentiation, the mechanism of memory consolidation
One synapse
fires in a particular temporal pattern, making it more likely that the
synapse will be activated by the same pattern in the future
The more the
synapse is activated, the more likely it will be activated in the
future, allowing stimuli and responses to be paired
FUNCTIONAL & CLINICAL CONSIDERATIONS
HIPPOCAMPUS
inability to form long-term memories
The hippocampus
is one of the first areas to undergo cell death in Alzheimer’s disease;
because it is important in consolidation of memories, individuals with
Alzheimer’s disease have difficulty in this area
CINGULATE GYRUS
akinesia, mutism, apathy, and indifference to pain
AMYGDALA
Lesions of the amygdala result in placidity, including loss of fear, rage, and aggression
An animal with a deficit in this area is not likely to last long
KLIIVER—BUCY SYNDROME
results from
bilateral destruction of the medial aspect of the temporal lobes,
including the amygdala and hippocampus, resulting in placidity,
hypersexuality, hyperphagia, and visual agnosia
MAMMILLARY BODIES AND THE DORSOMEDIAL NUCLEUS OF THE THALAMUS
Korsakoff syndrome
typically a result of thiamine deficiency (often seen in people with
alcoholism), leads to cell loss in the hippocampal formation and
results in amnesia, confabulation, and disorientation
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BASAL NUCLEI & THE EXTRAPYRAMIDAL (STRIATAL) MOTOR SYSTEM
A collection of subcortical nuclei involved in stereotyped and voluntary motor activity, the basal nuclei are the “chief” control system of the extrapyramidal motor system
The basal nuclei have no direct projection to the spinal cord; rather, they exert their influence indirectly
There are generally two pathways through the basal ganglia :
Direct - a movement activator
1°
(Motor cortex → Striatum) → 2° (GPi) → 3° (Lenticular fasciculus/Ansa
lenticularis → Thalamic fasciculus → VL of Thalamus) → 4°
(Thalamocortical radiations → Supplementary motor area) → 5° (Motor
cortex)
Indirect - a movement inhibitor
1°
(Motor cortex → Striatum) → 2° (GPe) → 3° (Subthalamic fasciculus →
Subthalamic nucleus) → 4° (Subthalamic fasciculus → GPi) → 5°
(Lenticular fasciculus/Ansa lenticularis → Thalamic fasciculus → VL of
Thalamus) → 6° (Thalamocortical radiations → Supplementary motor area)
→ 7° (Motor cortex)
Nigrostriatal pathway
Pars compacta → Striatum
BASAL NUCLEI (GANGLIA)
4 MAIN COMPONENTS
Caudate nucleus
Putamen
Globus pallidus
Amygdala
GROUPING OF THE BASAL NUCLEI
Striatum (neostriatum)
caudate nucleus - putamen
Lentiform nucleus
putamen - globus pallidus
Corpus striatum
lentiform nucleus - caudate nucleus
claustrum
EXTRAPYRAMIDAL (STRIATAL) MOTOR SYSTEM
COMPONENTS OF THE EXTRAPYRAMIDAL MOTOR SYSTEM - STRUCTURE
Neocortex
Striatum (caudatoputamen or neostriatum)
Globus pallidus (pallidum or paleostriatum)
Subthalamic nucleus
Thalamus
Ventral anterior nucleus
Ventral lateral nucleus
Centromedian nucleus
Substantia nigra
Pars compacta
Pars reticularis
Pedunculopontine nucleus
MAJOR CONNECTIONS OF THE EXTRAPYRAMIDAL SYSTEM
STRIATUM
Caudate + Putamen = Striatum
Receives input from neocortex all regions of cerebrum and from thalamus and substantia nigra
Output to globus pallidus and substantia nigra
Striatum activity inhibits activity of globus pallidus and substantia nigra
Influences pyramidal system through indirect connections
GLOBUS PALLIDUS
Forms medial-most part of lentiform nucleus (putamen forms lateral aspect)
Divided into external and internal parts by lamina medullaris
Receives input from striatum and subthalamic nucleus
External part projects to subthalamic nucleus via subthalamic fasciculus
Internal part projects to thalamus via thalamic fasciculus (lenticular fasciculus and ansa lenticularis)
and pedunculopontine nucleus
Primary output from the basal nuclei
SUBTHALAMIC NUCLEUS
Part of diencephalon
Receives inhibitory influence input from globus pallidus and motor cortex
Projects excitatory input to the internal segment of the globus pallidus
Regulates activity through basal nuclei
THALAMUS
ventral anterior, ventral lateral
mediodorsal nuclei
SUBSTANTIA NIGRA
Divided into a pars compacta and pars reticulata; pars compacta composed of cells pigmented with melanin
Both parts have reciprocal connections with striatum via striatonigral and nigrostriatal tracts
Pars reticulata projects to thalamus
Loss of dopaminergic neurons of pars compacta causes movement disorders; dopamine regulates activity through basal nuclei
Dopamine from
the substantia nigra has an excitatory influence on the D1 receptors in
the striatum, which facilitates the direct pathway,
while dopamine inhibits the D2 receptor, thusinhibiting activity through the indirect pathway
PEDUNCULOPONTINE NUCLEUS
globus pallidus
globus pallidus - substantia nigra
MAJOR NEUROTRANSMITTERS OF THE EXTRAPYRAMIDAL SYSTEM
Glutamate-containing neurons
striatal GABA-ergic and cholinergic neurons
GABA-containing neurons
GABA-ergic proiections
Dopamine-containing neurons
Neurons containing acetylcholine (ACh)
Neuropeptide-containing neurons
VENTRAL STRIOPALLIDAL COMPLEX & ITS CONNECTIONS
Ventral striatum
nucleus accumbens
Ventral pallidum
CLINICAL CORRELATIONS
Loss of dopaminergic cells in the substantia nigra pars compacta is involved in both Parkinson and Huntington disease
Damage to the subthalamic nucleus results in ballismus, which is a violent flailing of the limbs
Damage to the striatum leads to bilateral, large-scale, ongoing uncontrolled movements primarily seen in the limbs called choreas
PARKINSON DISEASE
degenerative disease
Results
depletion of dopamine - loss of melanin-containing dopaminergic neurons
Clinical signs
bradykinesia - hypokinesia - rigidity - resting tremor
Lewy bodies - Progressive supranuclear palsy
Treatment
pallidotomy - ventral thalamotomy
PROGRESSIVE SUPRANUCLEAR PALSY
METHYLPHENYLTETRAHYDROPYRIDINE (MPTP)-INDUCED PARKINSONISM
HUNTINGTON DISEASE (CHOREA)
inherited autosomal dominant movement disorder
degeneration of the cholinergic and g-aminobutyric acid (GABA)-ergic neurons
gyral atrophy
Glutamate (GLU) excitotoxicity
Clinical signs
choreiform movements - progressive dementia
hydrocephalus ex vacuo
OTHER CHOREIFORM DYSKINESIAS
Sydenham chorea (St. Vitus dance)
Chorea gravidarum
BALLISM & HEMIBALLISM
violent flinging (ballistic) movements of one or both extremities
ventrolateral thalamotomy
HEPATOLENTICULAR DEGENERATION (WILSON DISEASE)
autosomal recessive disorder - metabolism of copper
Clinical signs
Lesions
lentiform nucleus - corneal Kayser–Fleischer ring
Psychiatric symptoms
Diagnosis
Treatment
penicillamine - chelator
TARDIVE DYSKINESIA
repetitive choreic movement that affects the face and trunk
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CEREBRAL CORTEX
(Gould BRS 2019)
V1 PDF
OVERVIEW
NEOCORTEX ISOCORTEX HOMOGENETIC (90%) Motor thickest (4.5 mm) - visual thinnest (1.5 mm)
six-layered
ALLOCORTEX HETEROGENETIC (10%)
three-layered
Archicortex
hippocampus & the dentate gyrus
Paleocortex 3–5 layers paleocortex that serves as the transitional cortex between the neo- and archicortex
olfactory cortex
NEOCORTEX - 6-LAYERED
Neurons in various layers connect vertically to form small functionally related microcircuits, called columns
II & IV mainly afferent (i.e., receiving)
V & VI mainly efferent (i.e., sending)
LAYER I MOLECULAR
LAYER II EXTERNAL GRANULAR
LAYER III EXTERNAL PYRAMIDAL
It gives rise to association and commissural fibers and is the major source of corticocortical fibers
LAYER IV INTERNAL GRANULAR
It
receives thalamocortical fibers from the thalamic nuclei of the ventral
tier (i.e., ventral posterolateral and ventral posteromedial)
In the visual cortex (area 17), layer IV receives input from the lateral geniculate body
LAYER V INTERNAL PYRAMIDAL
It gives rise to corticobulbar, corticospinal, and corticostriatal fibers
It contains the giant pyramidal cells of Betz, which are found only in the motor cortex (area 4)
LAYER VI MULTIFORM
It is the major source of corticothalamic fibers
It gives rise to projection, commissural, and association fibers
FUNCTIONAL AREAS OF THE CEREBRAL CORTEX
divided into 47 cytoarchitectural areas, the Brodmann areas
The cerebral cortex accomplishes complex tasks by having associative areas : areas of the cerebral cortex responsible for related functions, integration, and higher processing.
Such areas may be classified as unimodal (dealing with a specific function) or multimodal (areas responsible for integrating one or more modalities for higher thought processing)
Examples of unimodal areas are the visual, auditory, much of the association cortex (i.e., visual association), premotor cortex, and supplementary cortex
Examples of multimodal areas are the prefrontal, parietal, and temporal cortices
Association areas function to produce meaning, quality, and texture to primary areas with which they are associated
SENSORY
PRIMARY SOMATOSENSORY CORTEX (AREAS 3,1, & 2)
Postcentral gyrus; paracentral lobule
somatotopically organized as sensory homunculus; primarily involved with localization of sensation - hypesthesia and astereognosis
SECONDARY SOMATOSENSORY CORTEX
SOMATOSENSORY ASSOCIATION CORTEX
Superior parietal lobule (areas 5 & 7)
involved with adding “meaning” to sensation (e.g., rough versus smooth, heavy versus light) - contralateral loss of tactile discrimination, stereognosis - statognosis
Supramarginal gyrus (area 40)
Integrates somatosensory, auditory, and visual sensation
PRIMARY VISUAL CORTEX (AREA 17)
Occipital lobe; vision - visual field deficits
SECONDARY & TERTIARY VISUAL CORTICES 18 & 19
visual hallucinations
VISUAL ASSOCIATION CORTEX (ANGULAR GYRUS [AREA 39])
involved with adding “meaning” to visual stimuli - contralateral homonymous hemianopia or lower quadrantanopia - Gerstmann syndrome
PRIMARY AUDITORY CORTEX (AREAS 41 AND 42)
Superior temporal gyrus; hearing - partial deafness
AUDITORY ASSOCIATION CORTEX (AREA 22)
language comprehension - speech area - planum temporale - sensory aphasia - sensory dysprosody
GUSTATORY CORTEX (AREA 43)
Parietal operculum and parainsular cortex; taste
VESTIBULAR CORTEX (AREA 2)
Postcentral gyrus; balance and equilibrium
MOTOR
PRIMARY MOTOR CORTEX (AREA 4)
Precentral gyrus; initiates voluntary movement - paracentral lobule
motor homunculus
contralateral upper motor neuron (UMN) lesion
urinary incontinence
PREMOTOR CORTEX (AREA 6)
Anterior to precentral gyrus on the frontal lobe; prepares primary motor cortex for activity
control of proximal and axial muscles
sympathetic apraxia
SUPPLEMENTARY MOTOR CORTEX (AREA 6)
Frontal lobe anterior to precentral gyrus; contains program for voluntary motor movement - programming complex motor sequences and in coordinating bilateral movements
speech deficits or aphasias
hypertonus of the flexor muscles
FRONTAL EYE FIELD (AREA 8)
Middle frontal gyrus; eye movement
conjugate deviation of the eyes toward the side of the lesion
HIGHER FUNCTION
PREFRONTAL CORTEX (AREAS 9—12)
Frontal lobe; personality, motivation, future planning, primitive reflexes
MOTOR (BROCA) SPEECH AREA (AREAS 44 AND 45)
Inferior frontal gyrus; motor aspect of speech
motor, expressive, nonfluent, or anterior aphasia
contralateral weakness of the lower face and arm and a sympathetic apraxia
SENSORY (WERNICKE) SPEECH AREA (AREA 22)
Superior temporal gyrus; speech comprehension
sensory, receptive, fluent, or posterior aphasia
ARCUATE FASCICULUS
fluent aphasia
paraphasic errors - object naming is impaired
CORPUS CALLOSUM
FOCAL DESTRUCTIVE HEMISPHERIC LESIONS AND SYMPTOMS
CEREBRAL DOMINANCE
Hemispheric dominance refers to the side of the brain where language centers are located
In the majority of people, this is the left hemisphere
DOMINANT HEMISPHERE
propositional language
astereognosis
NONDOMINANT HEMISPHERE
three-dimensional or spatial perception and nonverbal ideation
Lesions of the nondominant superior parietal lobule
contralateral loss of sensory discrimination
contralateral neglect
Lesions of the nondominant inferior parietal lobule
Lesions of the nondominant inferior frontal gyrus (areas 44 and 45)
expressive dysprosody
Lesions of the nondominant superior temporal gyrus (area 22)
receptive dysprosody
SPLIT—BRAIN SYNDROME
DESCRIPTION OF THE SPLIT BRAIN SYNDROME
disconnection syndrome
DEFICITS
anomia
alexia
OTHER LESIONS OF THE CORPUS CALLOSUM
ANTERIOR CORPUS CALLOSUM LESION
POSTERIOR CORPUS CALLOSUM (SPLENIUM) LESION
CALLOSOTOMY
BRAIN AND SPINAL CORD TUMORS
BLOOD SUPPLY TO THE MAJOR FUNCTIONAL CORTICAL AREAS
ACA
Territory
Occlusion: affected areas and deficits
MCA
Territory
Occlusion: affected areas and deficits
PCA
Territory
Occlusion: affected areas and deficits
LPCA
Territory
Occlusion: affected areas and deficits
JACKSONIAN SEIZURES (MARCH)
APRAXIA
the inability to perform motor activities in the presence of intact motor and sensory systems and normal comprehension
IDEOMOTOR APRAXIA (IDIOKENETIC APRAXIA)
IDEATIONAL APRAXIA (IDEATORY APRAXIA)
CONSTRUCTION APRAXIA
GAIT APRAXIA
APHASIA
is impaired or absent communication by speech, writing, or signs (i.e., loss of the capacity for spoken language)
The lesions are located in the dominant hemisphere
Associate the following symptoms and lesion sites with the appropriate aphasia
BROCA (MOTOR) APHASIA
WERNICKE (SENSORY) APHASIA
CONDUCTION APHASIA
TRANSCORTICAL MOTOR APHASIA
TRANSCORTICAL MIXED APHASIA
TRANSCORTICAL SENSORY APHASIA
GLOBAL APHASIA
THALAMIC APHASIA
BASAL NUCLEI
WATERSHED INFARCTS
DYSPROSODIES
are nondominant hemispheric language deficits that serve propositional language
Emotionality, inflection, melody, emphasis, and gesturing are affected
EXPRESSIVE DYSPROSODY
RECEPTIVE DYSPROSODY
TOC
NEUROTRANSMITTERS & PATHWAYS
(Gould BRS 2019) V1 PDF
INTRODUCTION
NEUROTRANSMITTERS
AMINO ACID-DERIVED
MAJOR EXCITATORY / INHIBITORY SYSTEMS
GLUTAMATE SYSTEM
Agmatine - Aspartic acid (aspartate) - Glutamic acid (glutamate) - Glutathione - Glycine - GSNO - GSSG - Kynurenic acid - NAA - NAAG - Proline - Serine
GABA SYSTEM
GABA GABOB GHB
GLYCINE SYSTEM
α-Alanine - β-Alanine - Glycine - Hypotaurine - Proline - Sarcosine - Serine - Taurine
GHB SYSTEM
GHB - T-HCA (GHC)
BIOGENIC AMINES
MONOAMINES
6-OHM - Dopamine - Epinephrine (adrenaline) - NAS (normelatonin) - Norepinephrine (noradrenaline) - Serotonin (5-HT)
TRACE AMINES
3-Iodothyronamine
- N-Methylphenethylamine - N-Methyltryptaminem - Octopamine
-p-Octopamine - Phenylethanolamine - Phenethylamine - Synephrine -
Tryptaminem -Tyramine - p-Tyramine
OTHERS
Histamine
NEUROPEPTIDES
HORMONES
OPIOID PEPTIDES
DYNORPHINS
Dynorphin A - Dynorphin A1–8 - Dynorphin B - Big dynorphin - Leumorphin α - Neoendorphin - β-Neoendorphin
ENDOMORPHINS
Endomorphin-1 - Endomorphin-2
ENDORPHINS
α-Endorphin - β-Endorphin - γ-Endorphin
ENKEPHALINS
Met-enkephalin - Leu-enkephalin
OTHERS
Adrenorphin - Amidorphin - Hemorphin(Hemorphin-4) - Nociceptin - Opiorphin -Spinorphin - Valorphin
OTHER NEUROPEPTIDES
KININS
Bradykinins - Tachykinins: mammal (Substance P - Neurokinin A Neurokinin B ) - amphibian Kassinin - Physalaemin
NEUROMEDINS
B - N - S -U
OREXINS
A - B
OTHER
Angiotensin-Bombesin-Calcitonin
gene-related peptide-Carnosine-Cocaine and amphetamine-regulated
transcript-Delta-sleep-inducing peptideFMRFamide-Galanin-Galanin-like
peptide-Gastrin-releasing peptide-GhrelinNeuropeptide AFNeuropeptide
FFNeuropeptide SFNeuropeptide VFNeuropeptide SNeuropeptide
YNeurophysinsNeurotensin-Pancreatic polypeptide-Pituitary adenylate
cyclase-activating peptideRVD-HpαVGF
LIPID-DERIVED
ENDOCANNABINOIDS
NEUROSTEROIDS
NUCLEOBASE-DERIVED
NUCLEOSIDES
ADENOSINE SYSTEM PURINES
ADP AMP ATP
VITAMIN-DERIVED
MISCELLANEOUS
CHOLINERGIC SYSTEM
Acetylcholine
GASOTRANSMITTERS
Carbon monoxide (CO) - Hydrogen sulfide (H2S) - Nitric oxide (NO)
CANDIDATES
Acetaldehyde - Ammonia (NH3) - Carbonyl sulfide (COS) - Nitrous oxide (N2O)- Sulfur dioxide (SO2)
NEUROCHEMICAL PATHWAYS & LOCI
Monoaminergic pathways = BIOGENIC-AMINE/MONOAMINE
Catecholaminergic pathways : dopamine, norepinephrine, & epinephrine
Indolaminergic pathways : Serotonin
Cholinergic pathways
Peptidergic pathways
Gamma-aminobutyric acid (GABA)—ergic pathways
Glutamatergic pathways
Glycinergic pathways
L-Arginine—nitric oxide pathway
NEUROTRANSMITTER SYSTEMS
BIOGENIC-AMINE/MONOAMINE
DOPAMINE
CHARACTERISTICS Regulated cognitive processes and behaviors
role in cognitive, motor, and neuroendocrine functions :
arousal (wakefulness)
aversion
cognitive control and working memory (co-regulated by norepinephrine)
emotion and mood
motivation (motivational salience)
motor function and control
positive reinforcement
reward (primary mediator)
sexual arousal, orgasm, and refractory period (via neuroendocrine regulation)
depleted in Parkinson disease
increased production in schizophrenics
DOPAMINERGIC PATHWAY - ORIGIN AND PROJECTIONS
VENTRAL TEGMENTAL AREA (VTA) PROJECTIONS
VTA → Amygdala
VTA → Cingulate cortex
VTA → Hippocampus
VTA → Ventral striatum (Mesolimbic pathway) Nucleus accumbens and olfactory tubercle - widely - behavior and schizophrenia
VTA → Olfactory bulb
VTA → Prefrontal cortex (Mesocortical pathway) - motivation and emotional response
NIGROSTRIATAL PATHWAY
Substantia nigra pars compacta → Dorsal striatum - Caudate nucleus and putamen - parkinsonism
TUBEROINFUNDIBULAR PATHWAY
Arcuate nucleus → Median eminence - Pituitary gland portal vessels - released dopamine inhibits the release of prolactin from the adenohypophysis
HYPOTHALAMOSPINAL PROJECTION
Hypothalamus → Spinal cord
INCERTOHYPOTHALAMIC PATHWAY
Zona incerta → Hypothalamus
ACETYLCHOLINE
CHARACTERISTICS
major
neurotransmitter of the peripheral nervous system, neuromuscular
junction, parasympathetic nervous system, preganglionic sympathetic
fibers, and postganglionic sympathetic fibers to the sweat glands
found in neurons of the somatic and visceral motor nuclei in the brainstem and spinal cord
receptors are
muscarinic (metabotropic; postganglionic parasympathetics and sweat
glands) or nicotinic (ionotropic; preganglionic sympathetic and
parasympathetic, by all or, (alpha beta, y motorneurons)
Regulated cognitive processes and behaviors :
arousal (wakefulness)
emotion and mood
learning
motor function
motivation (motivational salience)
short-term memory
reward (minor role)
CHOLINERGIC PATHWAYS
FOREBRAIN CHOLINERGIC NUCLEI (FCN) = NUCLEUS BASALIS OF MEYNERT + MEDIAL SEPTAL NUCLEUS + DIAGONAL BAND
FOREBRAIN NUCLEI PROJECTIONS
FCN → Hippocampus
FCN → Cerebral cortex
FCN → Limbic cortex and sensory cortex
NUCLEUS BASALIS OF MEYNERT → entire NEOCORTEX
located in the substantia innominata of the basal forebrain, between the globus pallidus and the anterior perforated substance
receives input from the locus ceruleus, raphe nuclei, substantia nigra, amygdala, and orbitofrontal and temporal cortices
degenerates in Alzheimer disease
SEPTAL NUCLEI (MEDIAL SEPTAL NUCLEUS) → FORNIX → HIPPOCAMPUS
STRIATUM - STRIATAL TONICALLY ACTIVE CHOLINERGIC NEURONS (TAN)
TAN → Medium spiny neuron
contains ACh in its local circuit neurons
has cholinergic neurons that degenerate in Huntington disease and Alzheimer disease
BRAINSTEM
CHOLINERGIC NUCLEI (BCN) = PEDUNCULOPONTINE NUCLEUS +
LATERODORSAL TEGMENTUM + MEDIAL HABENULA + PARABIGEMINAL
NUCLEUS
BRAINSTEM NUCLEI PROJECTIONS
BCN → Ventral tegmental area
BCN → Thalamus
NEOCORTEX
contains ACh in its local circuit neurons
NOREPINEPHRINE (NORADRENALINE) SYSTEM
CHARACTERISTICS
a catecholamine
the transmitter of the postganglionic sympathetic neurons
may play a role in the genesis and maintenance of mood
The catecholamine hypothesis of mood disorders states that reduced norepinephrine activity is related to depression and that increased norepinephrine activity is related to mania
Regulated cognitive processes and behaviors :
anxiety
arousal (wakefulness)
circadian rhythm
cognitive control and working memory (co-regulated by dopamine)
feeding and energy homeostasis
medullary control of respiration
negative emotional memory
nociception (perception of pain)
reward (minor role)
NORADRENERGIC PATHWAYS
LOCUS COERULEUS (LC) PROJECTIONS
contains the largest concentration of noradrenergic neurons in the central nervous system (CNS)
located in the pons and midbrain
projects to all parts of the CNS
receives input from the cortex, limbic system, reticular formation, raphe nuclei, cerebellum, and spinal cord
shows a significant loss of neurons in Alzheimer disease and Parkinson disease
hypothesized to play a role in anxiety and panic disorders
LC → Amygdala and Hippocampus
LC → Brain stem and Spinal cord
LC → Cerebellum
LC → Cerebral cortex
LC → Hypothalamus
LC → Tectum
LC → Thalamus
LC → Ventral tegmental area
LATERAL TEGMENTAL FIELD (LTF) (AREA) PROJECTIONS
located
in the medulla and pons. projects via the central tegmental tract and
the medial forebrain bundle to the hypothalamus and thalamus
LTF → Brain stem and Spinal cord
LTF → Olfactory bulb
SEROTONIN (5—HYDROXYTRYPTAMINE [5—HT]) SYSTEM
CHARACTERISTICS
mostly localized to GI tract where it regulates GI motility; not restricted to neurons
localized to raphe nuclei—plays a role in pain modulation
plays an important role in influencing arousal, sensory perception, emotion, and higher cognitive functions
the permissive serotonin hypothesis
states that reduced 5-HT activity permits reduced levels of
catecholamines, which is associated with depression, while elevated
levels are related to mania
severe depression and insomnia are associated with low 5-HT levels, and mania is associated with high 5-HT activity
Dysfunction of 5-HT is believed to underlie obsessive—compulsive disorder
tricyclic antidepressants and fluoxetine increase 5-HT availability by reducing its reuptake
Regulated cognitive processes and behaviors :
arousal (wakefulness)
body temperature regulation
emotion and mood, potentially including aggression
feeding and energy homeostasis
reward (minor role)
sensory perception
SEROTONERGIC PATHWAYS
5-HT neurons are found only in the raphe nuclei of the brainstem
Raphe nuclei project diffusely to the entire CNS
Raphe nuclei of the medulla project to the posterior horns of the spinal cord
Raphe nuclei of the pons project to the spinal cord and cerebellum
Raphe nuclei of the midbrain project to widespread areas of the diencephalon and the telencephalon, including the striatum
CAUDAL NUCLEI (CN) = RAPHE MAGNUS + RAPHE PALLIDUS + RAPHE OBSCURUS
CAUDAL PROJECTIONS
CN → Cerebral cortex
CN → Thalamus
CN → Caudate-putamen and nucleus accumbens
CN → Substantia nigra and ventral tegmental area
CN → Cerebellum
CN → Spinal cord
ROSTRAL NUCLEI (RN) = NUCLEUS LINEARIS + DORSAL RAPHE + MEDIAL RAPHE + RAPHE PONTIS
ROSTRAL PROJECTIONS
RN → Amygdala
RN → Cingulate cortex
RN → Hippocampus
RN → Hypothalamus
RN → Neocortex
RN → Septum
RN → Thalamus
RN → Ventral tegmental area
PINEAL GLAND (EPIPHYSIS CEREBRI)
contains the highest concentration of 5-HT in the CNS; however, the vast majority (85%—90%) is found in the gut
contains pinealocytes, which convert 5-HT to melatonin
HISTAMINE
CHARACTERISTICS
Regulated cognitive processes and behaviors :
arousal (wakefulness)
feeding and energy homeostasis
learning
memory
HISTAMINERGIC PATHWAYS
TUBEROMAMMILLARY NUCLEUS (TMN) PROJECTIONS
TMN → Cerebral cortex
TMN → Hippocampus
TMN → Neostriatum
TMN → Nucleus accumbens
TMN → Amygdala
TMN → Hypothalamus
ADRENALIN
CHARACTERISTICS
Regulated cognitive processes and behaviors :
medullary control of respiration
sympathetic nervous system
feeding and energy homeostasis
arousal
stress
ADRENERGIC PATHWAYS
ROSTRAL VENTROLATERAL MEDULLA (RVLM) PROJECTIONS
RVLM → Spinal cord
RVLM → Brain stem
RVLM → Hypothalamus
OPIOID PEPTIDE
ENDORPHINS
derived from three peptide precursors: 1) pro-opiomelanocortin, the precursor of adrenocorticotropic hormone; 2) proenkephalin; and 3) prodynorphin
include beta-endorphin, the major endorphin found in the brain
endorphinergic neurons are found primarily in the hypothalamus (arcuate and premammillary nuclei)
These neurons
project to the hippocampus, amygdala, nucleus accumbens, septal area,
thalamus, and locus ceruleus (midbrain and pons). play a major role in
endocrine function
ENKEPHALINS
all three precursors produce enkephalin
the most widely distributed and abundant opioid peptides
found in highest concentrations in the globus pallidus
synthesized in striatal neurons, which project to the globus pallidus
located mainly in local circuits of the limbic and striatal systems
coexist with dopamine, norepinephrine, ACh, and GABA
play a role in pain suppression in the posterior horn ofthe spinal cord
DYNORPHINS
derived from prodynorphin
follow, in general, the distribution map for enkephalin
found in high concentrations in the limbic system and hypothalamus
NONOPIOID NEUROPEPTIDES
SUBSTANCE P
a modulatory neurotransmitter
found in spinal ganglion cells, which project to the substantia gelatinosa
plays a role in pain transmission (in A—delta and C fibers) and inflammatory processes
synthesized in striatal neurons, which project to the globus pallidus and the substantia nigra
SOMATOSTATIN (SOMATOTROPIN-RELEASE–INHIBITING FACTOR)
somatostatinergic
neurons are found in the anterior hypothalamus and in the preoptic
region, striatum, amygdala, cerebral cortex, and in spinal ganglion
cells
somatostatinergic neurons from the anterior hypothalamus project their axons to the median eminence
involved in endocrine system regulation—somatostatin enters the
hypophyseal portal system and regulates the release of growth hormone and thyroid-stimulating hormone
AMINO ACIDS
INHIBITORY AMINO ACID TRANSMITTERS
GABA
can be localized by the marker glutamic acid decarboxylase
the major inhibitory neurotransmitter of the brain
coexists with substance P and with enkephalin
Purkinje, stellate, basket, and Golgi cells of the cerebellar cortex are GABA-ergic
GABA-ergic striatal neurons project to the globus pallidus and the substantia nigra
GABA-ergic pallidal neurons project to the thalamus
GABA-ergic nigral neurons project to the thalamus
Rostromedial tegmental nucleus
GLYCINE
the major inhibitory neurotransmitter of the spinal cord
used by the Renshaw cells of the spinal cord
its inhibitory action is blocked by strychnine
EXCITATORY AMINO ACID TRANSMITTERS
GLUTAMATE
a major excitatory neurotransmitter of the brain; 60% of brain synapses are glutamatergic
the neurotransmitter of the cerebellar granule cell
used by the corticobulbar and corticospinal tracts
used by spinal ganglion cells
believed to be involved in long-term potentiation of hippocampal neurons Via N-methyl-D-aspartate receptors
plays a role in kindling-induced seizures
plays a role in pain transmission (in A—delta and C fibers)
thalamus globus pallidus
neocortical glutamatergic neurons project to the striatum, the subthalamic nucleus,and the thalamus
The subthalamic nucleus projects glutamatergic fibers to the globus pallidus
ASPARTATE
a major excitatory transmitter 0f the brain.
the transmitter 0f the climbing fibers of the cerebellum
NITRIC OXIDE
a gaseous neurotransmitter that is produced when nitric oxide synthase converts arginine to citrulline
located in the olfactory system, striatum, cortex, hippocampal formation, supraoptic nucleus of the hypothalamus, and cerebellum
responsible for the smooth muscle relaxation of the corpus cavernosum and thus penile erection
believed to play a role in memory formation (long-term potentiation in the hippocampal formation)
FUNCTIONAL & CLINICAL CORRELATIONS
ENDOGENOUS PAIN CONTROL SYSTEM
Ascending pathway
Descending raphespinal pathway
Descending ceruleospinal pathway
PARKINSON DISEASE
degeneration of dopaminergic neurons
reduction of dopamine
HUNTINGTON DISEASE (CHOREA)
loss of ACh- and GABA-containing neurons
loss of GABA
ALZHEIMER DISEASE
degeneration of cortical neurons and cholinergic neurons
60% to 90% loss of choline acetyltransferase
MYASTHENIA GRAVIS
muscle paresis
LAMBERT–EATON MYASTHENIC SYNDROME
TOC
REFERENCES
ANATOMY
NEUROANATOMY
REF
ANATOMY
REF
AUTHORS
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General Anatomy and Musculoskeletal System - https://archive.org/details/emb00065/mode/2up
Neck and Internal Organs - https://archive.org/details/emb00066/mode/2up
Head and Neuroanatomy - https://archive.org/details/emb00067/mode/2up
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REF
TOPICS
OVERVIEW
wikipedia.org/wiki/Outline_of_human_anatomy
REF
NEUROANATOMY
REF
AUTHORS
Barker. Neuroanatomy & Neuroscience at a Glance. 5e. 2017. [ 192 pages ]
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Gould. Sidman's Neuroanatomy: A Programmed Learning Tool. 2e. 2007. [ 859 pages ] [ Download ]
Singh. Textbook of Clinical Neuroanatomy. 4e. 2020. [ 282 pages ] [ Download ]
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REF
TOPICS
OVERVIEW
https://en.wikipedia.org/wiki/List_of_regions_in_the_human_brain
PATHWAYS
https://en.wikipedia.org/wiki/Neural_pathway
https://en.wikipedia.org/wiki/Neurotransmitter
https://en.wikipedia.org/wiki/Neuropeptide
COMMUNICATING RAMI
https://en.wikipedia.org/wiki/Ramus_communicans
AUTONOMIC NERVOUS SYSTEM
https://en.wikipedia.org/wiki/Autonomic_nervous_system
REF
MORE REFERENCES
Wayback Machine
TOC