Anatomy of the Spinal Cord and Peripheral Nervous System PDF

FAKULTAS Anatomy of the spinal cord and the KEDOKTERAN peripheral nervous system Anatomi medula spinalis dan sistem saraf tepi Dr. dr. Aditya Hernowo https://thumbs.imagekind.com/3459149_650/Spinal-Cord_a...

FAKULTAS Anatomy of the spinal cord and the KEDOKTERAN peripheral nervous system Anatomi medula spinalis dan sistem saraf tepi Dr. dr. Aditya Hernowo https://thumbs.imagekind.com/3459149_650/Spinal-Cord_art.jpg?v=1554490657  LOCATION FAKULTAS KEDOKTERAN Extend from foramen magnum to the LV 1 –LV 2 junction (lower border if lumbar vertebra 1 or upper border of LV 2). It terminates at L1-2 in adults and at L3-L4 in infants.  LOCATION FAKULTAS KEDOKTERAN Centrally has gray matter. Peripherally has white matter. Gray matter has dorsal and ventral horns. Lateral horn is present only in TV 1 to LV 2 region (sympathetic neurons) Ventral white commissure is present in front of the central canal TI-L2 o sympathers neurons FAKULTAS KEDOKTERAN Structure of Spinal Cord Dorsal (posterior) horns- sensory neurons Ventral (anterior) horns- motor neurons (LMN) Lateral horns- autonomic (motor) neurons sensoria Dorsal · Ventral a MotOriC Lateral · otonum FAKULTAS KEDOKTERAN Enlargements in spinal cord pembesaran uniuh Cervical enlargement cervical inervasi A swelling in the spinal cord OtOtV in the region of C3-4 to member uneustremitas T1-2, supplies the upper plexus brachialis limb muscles. (3-4 upic enstremitas uniuh Lumbar enlargement atas A swelling in the spinal cord gerdhaneaths in the region of T10-12 to L1-2, supplies the lower limb muscles. T10-12 0 (1-2 enstremitas bawah cuplai otot ? La membentur plexus lumbosacralls  Conus medullaris and filum terminale The tapering lower end of the Conus spinal cord is called the conus medullaris medullaris. Filum terminale is a slender Filum thread like prolongation of the terminale pia mater. Starting from conus medullaris extends up to the back of coccyx. Stabilizes the spinal cord within the vertebral canal. FAKULTAS KEDOKTERAN Cauda equina The spinal nerve roots (lumbosacral) in the lower part of the vertebral canal in the region of the lower lumbar vertebrae, sacrum and coccyx. Resembles a "horse's tail."  Spinal Meninges FAKULTAS KEDOKTERAN Pia mater Arachnoid mater Dura mater FAKULTAS KEDOKTERAN Spaces around the cord The epidural space exits as a potential space, between the dura and the periosteum of vertebral canal. Contains internal vertebral venous plexus and used for injection of anesthesthetic agents. - bagian epiduralaya di FAKULTAS KEDOKTERAN Lumbar Puncture The spinal cord ends at the intervertebral disc between L1 and L2 in adult, so the lower part of the vertebral canal does not contain the spinal cord. Hollow needles can be safely inserted into the subarachnoid space to remove CSF for diagnostic procedures (Lumbar Puncture at L3-L4 in adult). FAKULTAS KEDOKTERAN Lumbar puncture Anterior Median Fissure and Posterior Median Sulcus FAKULTAS KEDOKTERAN ❖ Anterior median fissure is the groove along the anterior midline of the spinal cord that incompletely divides it into symmetrical halves. ❖ Posterior median sulcus lies in the posterior midline of the spinal cord. FAKULTAS KEDOKTERAN Spinal segment The part of the spinal cord that gives rise to a pair of spinal nerves is called a “spinal segment.” There are 31 spinal segments. FAKULTAS PNS (Peripheral Nervous System) KEDOKTERAN cranial nerves · PNS Composed of a spinal nerves CNS ○ Cranial nerves (12 pairs) Ganglion - ○ Spinal nerves (31 pairs) ○ Ganglions PNS FAKULTAS KEDOKTERAN Spinal nerve (peripheral nerve) Is formed by the union of dorsal and ventral roots. Dorsal root There are 31 pairs of spinal nerve. cervical 8 : Spinal Cervical – 8 12 nerve Thorncal : Thoracic – 12 Lumbar : 5 Lumbar – 5 Ventral sacral = 5 Sacral – 5 root : Coccygeal – 1 colcygeal FAKULTAS KEDOKTERAN Spinal nerve (peripheral nerve) It is formed by the union of ventral (motor) and dorsal (sensory) roots. There is an enlargement on the dorsal root and It is known as dorsal root ganglion. The 2 roots unite to form a spinal nerve (mixed). After a course of a few mm, the spinal nerve divides into a ventral and dorsal rami. FAKULTAS KEDOKTERAN Spinal nerve (peripheral nerve) The dorsal ramus passes backwards and divides into medial and lateral branches and supply the muscles of the back and skin covering them. The ventral ramus supplies the Losuplai muscles and skin of the anterior 3/4 dinding 3/4 of the body wall. fubuh Spinal nerves and their branches also carry efferent fibres of the nerms-defferent fibres - sympathetic sympathetic nervous system. spinal FAKULTAS KEDOKTERAN Functional components in spinal nerves General Somatic Afferent (GSA) – General sensation from the body wall General Visceral Afferent (GVA) - General sensation from viscera General Somatic Efferent (GSE) – Motor supply to the skeletal muscle of the body wall General Visceral Efferent (GVE) - Motor supply to the smooth muscle of viscera (sensor y) (GSA) (GVA) (GVE) (GSE) FAKULTAS Functional components in spinal nerves ventual KEDOKTERAN Dorsal-POSA "OSE DEVA Root Root LEVE Dorsal root contains General Somatic Afferent (GSA) and General Visceral Afferent (GVA). Ventral root contains (GSA) General Somatic Efferent (GVA) (GSE) and General (GVE) Visceral Efferent (GVE). (GSE) Spinal nerve contains all four components, GSA, GVA, GSE and GVE. FAKULTAS KEDOKTERAN Levels (regions) of the spinal cord and differences FAKULTAS KEDOKTERAN Ligamentum denticulatum ↳ untun menstabilian posisi spinal cord cord Melindungi spinal * The spinal cord is piamater & a letanya antara suspended in the dural sac dura mater by pairs of tooth-like ligaments made up of pia mater called “Denticulate ligaments”. Its function is to stabilizes the spinal cord in position. FAKULTAS KEDOKTERAN Ligamentum denticulatum C There are 21 pairs of. 21 penghusury these ligaments, each arising from the side of the spinal cord midway between the dorsal and ventral nerve roots. FAKULTAS KEDOKTERAN Blood supply of the spinal cord It is supplied by 3 longitudinal vessels. One anterior spinal artery and two posterior spinal arteries. spinal (1) 29 anterior. suplai spinal cord A u. posterio - spinal (2) FAKULTAS KEDOKTERAN Anterior Spinal Artery Arises from vertebral arteries. Runs down the entire length of the spinal cord in the anterior median fissure and supplies the anterior ⅔ of the spinal cord. dari arteri vertebral - Anterior spinal arterly a mensuplai 2/3 spinal cord FAKULTAS KEDOKTERAN Posterior Spinal Arteries Arises from either the vertebral arteries or the posterior inferior cerebellar arteries(PICA). Supply the post ⅓ of the spinal cord. vertebral & a dari A posterior. posterior inferior cerebellar CPICA) Spinal asuplai 1/3 spinal cord FAKULTAS KEDOKTERAN Radicular arteries (feeder dorsal arteries) spinal ventual foramina intervertebral a aliran suplai : a & root nerves Feeder arteries enter through J the intervertebral foramina Spinal and pass along the ventral and cord dorsal roots of the spinal nerves to reach the spinal cord. They are branches of the deep cervical, intercostals and - divical intercostal lumbar arteries. A. radicular a lumbar FAKULTAS KEDOKTERAN The Great Radicular Artery (Artery of Adamkiewicz) arteri Adamhiewicz : diatas One large and important artery arises vertebral & from the aorta in the lower thoracic or cumbar upper lumbar vertebral levels known as dibawan the great anterior medullary artery of thorucal Adamkiewicz. It is unilateral and in majority of persons enters the spinal cord from the left side. It is the major source of blood to the lower 2/3 of the spinal cord. FAKULTAS KEDOKTERAN Clinical relevance ❖ Occlusion of an anterior spinal artery often produces ischaemia of the anterior 2/3 of the cord causing flaccid paralysis and loss of pain and temperature sensation. ❖ Damage to the great radicular artery may seriously affect the functions of the lower part of spinal cord and cause muscular weakness and paralysis. FAKULTAS KEDOKTERAN Venous drainage The veins of the spinal cord are distributed similar to the arteries. These veins communicate with each other and are drained via radicular veins, then to intervertebral veins, vertebral veins, ascending lumbar veins, and to the azygos system. FAKULTAS KEDOKTERAN Tracts in the spinal cord The white matter of the cord consists of ascending and descending tracts (nerve fibers) embedded in neuroglia. FAKULTAS KEDOKTERAN Major Sensory or Ascending Tracts Fasiculus Fasiculus cuneatus gracilis Posterior spinocerebellar tract Anterior spinocerebellar tract Lateral spinothalamic tract Anterior spinothalamic tract  Major Sensory or Ascending Tracts Name Location Function Fasciculus gracilis Posterior Column Conscious proprioception, vibration & two-point discrimination Fasciculus Cuneatus Posterior Same as FG Column Lateral Spinothalamic Lateral Pain and thermal sensations Column Anterior Anterior Pressure and Crude touch Spinothalamic Column sensations Posterior and Lateral Unconscious proprioceptive Anterior Column information. Spinocerebellar FAKULTAS KEDOKTERAN Major Motor or Descending Tracts Lateral corticospinal tract Rubrospinal tract Vestibulospinal tract Tectospinal Anterior tract corticospinal tract Motor or Descending Tracts of the Spinal Cord Name Location Function Lateral Corticospinal Lateral Controls muscles of the limbs, hands and Column feet Anterior Anterior Controls muscles of the axial skeleton Corticospinal Column Rubrospinal Lateral Controls tone of the flexor muscles of the Column limbs, hands, and feet Tectospinal Anterior Controls skeletal muscles of the head and Column eyes in response to visual stimuli Vestibulospinal Anterior column Controls muscle for maintaining balance in response to head movements FAKULTAS KEDOKTERAN Important levels The adult spinal cord is (45cm) in length and considerably shorter than its vertebral column so the spinal segments and the vertebral levels do not correspond.  Important levels Spinal segment Vertebral level (spines) Cervical 1-8 Foramen magnum to C6 (add 1 to the spine) Thoracic 1-6 C6 –T4 (add 2 to the spine) Thoracic 7 –12 T4-T9 (add 3 to the spine) Lumbar and sacral T10 - L1 FAKULTAS Syringomyelia KEDOKTERAN (dilatation of central canal) Usually beginning in the cervical region. It erodes the ventral white commissure which contains decussating spinothalamic fibers. So, there will be bilateral loss of pain and temperature in the affected region. Touch and proprioception are not affected. FAKULTAS Brown Sequard Syndrome KEDOKTERAN (Hemisection of the spinal cord) Both ascending and descending tracts are involved. Ventral and dorsal horns are also involved. FAKULTAS KEDOKTERAN Upper motor neuron & Lower motor UMN neuron Upper motor neurons Motor neurons in the brain and their axons (called corticospinal and corticobulbar tracts). Lower motor neurons Motor neurons in anterior horn of the UMN spinal cord and their axons. Motor neurons of cranial nerve and LMN their axons (nerve) LMN  Barbinski’s sign (+) (-)/ normal Babinski's reflex occurs when the big toe moves toward the top surface of the foot and the other toes fan out after the sole of the foot has been firmly stroked. 12 Pairs of Cranial Nerves FAKULTAS KEDOKTERAN Cranial Nerves Nerves that arise from the brain Origin—nuclei in the brain (mainly brain stem) Superficial attachment Intracranial course Foramen of exit/entrance Extracranial course Functional components: Structures of supply- muscle (motor), mucosa,skin,special sense (sensory),glands (autonomic)……GSE,SVE,GVE ,GSA,SVA,SSA…… Lesions of cranial nerves- Corticobulbar tracts UMN lesion Below the nuclei origin—LMN lesion Types of Cranial Nerve-acc to functional components Blue=Sensory Green=Motor Red=Mixed FAKULTAS KEDOKTERAN Functional Components of Cranial Nerves Sensory: I Olfactory , II Optic , VIII Vestibulocochlear Motor III Oculomotor, IV Trochlear: VI Abducent, XI Accessory , XII Hypoglossal Mixed Sensory & Motor: V Trigeminal, VII Facial, IX Glossopharyngeal , X Vagus Parasympathetic: III Oculomotor, VII Facial, IX Glosso-pharyngeal , X Vagus Superficial Attachment & Origin of Cranial Nerves in the Brain Stem FAKULTAS KEDOKTERAN OLFACTORY NERVE: The First Cranial Nerve The olfactory nerve has only a special sensory component. (special afferent)- Functions in the special sense of smell or olfaction. The olfactory system consists of the ○ olfactory epithelium, bulbs and tracts along with ○ olfactory areas of the brain collectively known as the rhinencephalon. The Nasal Cavity, Olfactory Epithelium & Olfactory Nerves The olfactory chemoreceptors are located on the cilia of bipolar neurons.  Rhinecephalon (Smell Brain) Primary (lateral) olfactory area-consists of the cortex of the uncus and the anterior part of the hippocampal gyrus-most fibers project to this area Area 28 Medial olfactory area - located in the septal region of the medial surface of the frontal lobe. Via its connections with the limbic system, this area is thought to mediate the emotional response to odors. Hippocampus ,uncus  OPTIC NERVE:2nd Cranial Nerve The optic nerve has only a special sensory component. Special sensory conveys visual information from the retina (special afferent). The optic nerve travels postero-medially from the eye to exit the orbit via optic canal. It enters middle cranial fossa where it joins other optic nerve to form optic chiasma where nasal-side fibres cross, temporal fibres do not. Optic tract fibres synapse at lateral geniculate body of thalamus where new neurons begin as optic radiation to travel to the visual cortex in area 17 of the occipital lobe. The Neuronal Chains In Visual Pathway 1st neurone =Photoreceptor cells (rods & cones of retina) 2nd neurone=Bipolar cells (R) 3rd neurone=Ganglion cells -R Afferent fibres =Optic nerve-Optic chiasma--Optic tract 4th neurone=lateral geniculate body (Thalamus)-optic radiations to Striae (calcarine) cortex visual area in occipital lobes area 17 Normal Visual Field and Visual field defects Normal visual field Bitemporal hemianopia Binasal hemianopia Left homonymous hemianopia Right homonymous hemianopia  Damage to Retina & Optic Nerve Damage to the retina results in a loss of input from the affected portion of the retina leading to a monocular field deficit. Damage to the optic nerve will also result in a monocular visual defect due to loss of input from the ipsilateral eye. The patient will complain of blindness in that eye. Lesion of the optic chiasma ⚫ Damage to the medial aspect of the optic chiasma, (B) as is often seen with a pituitary gland tumor, may compromise the decussating fibers from both nasal hemiretinas. The loss of peripheral vision in both eyes is called bitemporal hemianopia. ⚫ Defects are described with reference to the visual fields and not to the retina Lesion of Optic tract& Optic radiation / Visual Cortex Left homonymous hemianopia (for the lesion on the right tract) Visual Field Defects-Summary lesion at the left optic radiation gives a right homonymous. Can be caused by stroke, Space occupying lesions Defect Location Loss of vision in one eye Ipsilateral Optic Nerve Bitemporal Hemianopia Optic chiasma Binasal hemianopia Optic chiasma Left homonymous hemianopia Right optic tract / radiation Right homonymous hemianopia Left optic tract / radiation 3rd ,4th & 6th,Cranial Nerves & Extraocular Muscles-RL6SO4R3  THE OCULOMOTOR NERVE: The Third 3rd Cranial Nerve 1. somatic motor component of CN III plays a major role in controlling the muscles responsible for the precise movement of the eyes for visual tracking or fixation on an object. 2. visceral motor component is involved in the pupillary light and accommodation reflexes.  Origin of 3rd Cranial Nerve oculomotor nucleus (somatic motor component) ○ located in the rostral midbrain at the level of the superior colliculus ventral to aqueduct near the midline Edinger-Westphal nucleus Parasympathetic component (visceral motor ) Fibers emerge in the interpeduncular fossa at the junction of the midbrain and pons Edinger-Westphal Nucleus ; Pretectal area & Pupillary reflexes The CN III is involved in the pupillary light and accommodation reflexes. Fibers from EW form the Efferent pathway of pupillary reflex as they form parasympathetic innervation of the constrictor pupillae and ciliary muscles of the eye. The optic nerve is the afferent pathway. The Argyll-Robinson Pupil: Loss of light reflex with preservation of accommodation reflex due to neurosyphilis or tumors near posterior part of 3rd ventricle (pretectal area) Intracranial course of 3rd Cranial nerve The 3rd nerve course ventrally through the midbrain, interpeduncular fossa, runs along the lateral wall of the cavernous sinus just superior to the trochlear nerve and enters the orbit via the superior orbital fissure. Supplies the extraocular muscles EXCEPT superior oblique & lateral rectus  3rd Cranial Nerve Palsy Causes: a lesion of cranial nerve nuclei in mid brain or by compression of peripheral course by aneurysm or tumour or cavernous sinus thrombosis Signs and symptoms: 1. Drooping of eyelids (ptosis) The eyelid is held up by the levator palpebrae superioris muscle, which is innervated by the oculomotor nerve). 2. Dilatation of pupil that is unresponsive to light and accomodation (provides parasympathetic innervation for the sphincter pupillae muscle of the iris and for the ciliary muscle of accommodation) 3. Inability of the eyes to move downwards, upwards and inwards (adduction) 4. Diplopia 3rd,4th,6th nerves may be injured together within the cavernous sinus or at the entrance into the orbit at the superior orbital fissure Trochlear Nerve;4th Cranial Nerve Overview The trochlear nerve has only a somatic motor component: (general somatic efferent) Somatic motor innervates the superior oblique muscle of the CONTRALATERAL orbit. Origin and central course originate from the trochlear nucleus located in the tegmentum of the midbrain at the level of the inferior colliculus  TROCHLEAR NERVE (4th Cranial Nerve) Unique Features: The trochlear nerve has several features that make it unique from the other cranial nerves: IT Is the only nerve to exit from the dorsal surface of the brain. Is the only nerve in which all the lower motor neuron fibres decussate.(supplies contralateral muscle) Has the longest intracranial course.(likely to be involved in head trauma) Has the smallest number of axons. Trochlear Nerve Palsy ○ Due to paralysis of Superior Oblique the eye cannot turn inward and downward resulting in vertical diplopia. (the images were situated on top of each other vertically ). ○ This is often reported as difficulty in descending stairs. ○ Contralateral head tilt. The person tends subconciously to tilt the head thereby using eye muscles that are unaffected by the palsy. This position can eliminate the double vision. A child with left trochlear nerve palsy tilts her head to the right Tilting to the left makes the nerve palsy more obvious  THE ABDUCENT NERVE: 6th Cranial nerve It has only a somatic motor (general somatic efferent) component. innervates the lateral rectus muscle of the ipsilateral orbit. The lateral rectus muscle is responsible for lateral gaze (its contraction causes the eye to be abducted)  Origin of Abducent Nerve It originate from the abducens nucleus ○ located in the caudal pons at the level of the facial colliculus. ○ just ventral to the fourth ventricle near the midline. Axons of CN VII (facial nerve) loop around the abducens nucleus and give rise to a bulge in the floor of the fourth ventricle - the facial colliculus. Fibers of 6th nerve travel ventrally to exit the brainstem at the pontomedullary junction. TS of Lower Part of the Pons.  Intracranial course and final innervation The abducens nerve travels along the medial wall of the cavernous sinus with CN III, IV, and V. enters the orbit through the superior orbital fissure. CN VI passes through the tendinous ring of the extraocular muscles and innervates the lateral rectus muscle  Lesion of Abducens nerve Lower motor neuron (LMN) lesion Damage to the abducens nucleus or its axons results in weakness or paralysis of the ipsilateral lateral rectus muscle. Eye cannot look outwards This is indicated by: Medially directed eye on the affected side and there will be horizontal diplopia.  SUMMARY FAKULTAS KEDOKTERAN CN FORAMINA FUNCTION I Cribiform plate Special sensory ⇒ smell II Optic canal Special sensory ⇒ sight III SOF Somatomotor ⇒ all except for SO and LR Visceromotor ⇒ sphinchter pupillae IV SOF Somatomotor ⇒ SO VI SOF Somatomotor ⇒ LR  Cranial Nerve Attachments to the Brain Stem FAKULTAS KEDOKTERAN FAKULTAS KEDOKTERAN TRIGEMINAL N : CN V …3 sensory nuclei and 1 motor nucleus  FAKULTAS Anatomy of the spinal cord and the KEDOKTERAN peripheral nervous system TRIGEMINAL N : CN V …3 sensory nuclei and 1 motor nucleus FAKULTAS KEDOKTERAN Trigeminal Nerve Nuclei NUCLEI FUNCTIONS Mesencephalic nucleus For proprioception Pontine nucleus or Main Tactile/ discriminative touch sensory nucleus Spinal tract nucleus Pain and temperature Motor nucleus For muscles of mastication FAKULTAS Central connections of the Trigeminal Nerve KEDOKTERAN Nuclei Thalamic VPM Spinal nucleus FAKULTAS KEDOKTERAN TRIGEMINAL NERVE- divisions and entrance foramen V1:Opthalmic branch--- Sup Orbital Fissure V2: Maxillary branch--- Foramen Rotundum V3:Mandibular branch ----Foramen Ovale FAKULTAS KEDOKTERAN FAKULTAS KEDOKTERAN Trigeminal (V) CN-Functional components The sensory portion of the trigeminal supplies touch–pain–temperature to the face thru V1 V2 V3 divisions. Ophthalmic V1-supplies the region developed from the frontonasal process (corneal reflex afferent) Maxillary V2- supplies region developed from maxillary process of the 1st pharyngeal arch Mandibular V3–supplies region developed from mandibular process +Motor to muscles of mastication (jaw jerk),Tensor Tympani and Tensor palatini General Sensation to oral& nasal cavity, teeth & paranasal sinuses + antr 2/3 of the tongue Proprioceptive fibers to underlying facial muscles FAKULTAS KEDOKTERAN Lesion of Trigeminal Nerve Trigeminal Neuralgia - pain in the distribution of any branch of the trigeminal nerve esp.maxillary & mandibular Herpes zoster infection of sensory roots of Trigeminal Nerve leads to pain & eruption of vesicles of dermatome supplied by ophthalmic, maxillary & mandibular branches. Syringobulbia(central cavitation of the medulla caudal to the 4th ventricle-destruction of trigeminothalamic fibers) leads to selective loss of pain & temperature sensibility in the face. Inability to contract muscles of mastication, deviation of mandible to side of lesion when mouth is opened The jaw jerk is one of the deep tendon or stretch reflexes. When it is normal, tapping the mandible produces a brisk contraction. When abnormal, with upper motor neuron lesions, there is a hyperactive or repeating reflex (clonus). With nuclear or infranuclear lesions, the reflex is absent. FAKULTAS Anatomy of the spinal cord and the KEDOKTERAN peripheral nervous system Facial Nerve (7th Cranial Nerve) Origin of Cranial Nerve Nuclei in Brain stem Intracranial &Extracranial Course of Facial Nerve Functional Components of the Facial Nerve & Nuclei(origin) 7,9,10 Solitary nucleus for taste FAKULTAS Functional Components of Facial Nerve KEDOKTERAN 1. Brancial motor(special visceral efferent SVE) ○ Supplies the muscles of facial expression (Corneal reflex efferent); posterior belly of digastric muscle; stylohyoid, and stapedius. 2. Visceral motor(general visceral efferentGVE) ○ Parasympathetic innervation of the lacrimal, submandibular, and sublingual glands, as well as mucous membranes of nasopharynx, hard and soft palate 3. Special sensory(special afferent SSA) ○ Taste sensation from the anterior 2/3 of tongue; hard and soft palates. 4. General sensory(general somatic afferent GSA) ○ General sensation from the skin of the concha of the auricle and from a small area behind the ear. It may also supplement the mandibular division of CN V in providing sensation from the wall of the acoustic meatus and the outer surface of the tympanic membrane.  Special Sensory of Facial Nerve Chorda tympani (VII) joins Lingual (V) for taste-antr 2/3 of tongue FAKULTAS KEDOKTERAN Bell’s Palsy-(Lower motor neurone lesion) Lesion of Facial Nerve: Bell's palsy -swelling of nerve in facial canal S/S: pain around ear; paralysis of the facial muscles; inability to close eye; drooping mouth leads to drooling hyperacusis on affected side; Loss of secretion from submandibular and sublingual glands ipsilateral to the lesion (lesion of the chorda tympani, visceral motor) Loss of taste from anterior 2/3 of tongue ipsilateral to the lesion (chorda tympani, special sensory ) Bell's palsy (LMN lesion of facial nerve) Trouble raising his left eyebrow and wrinkling the left side of his forehead (shown in A) Trouble closing his left eye and raising the left corner of his mouth (shown in B) Drooping at the left corner of his mouth and trouble closing his left eye (shown in C) http://medicine.ucsd.edu/clinicalimg/neuro-centr al-CN7-palsy2.html. Upper Motor Neurone Lesion ; Facial palsy e g Stroke facial paralysis below the eye on the opposite side FAKULTAS KEDOKTERAN Clinical Signs Suggesting Site of Facial Nerve Lesion Upper facial territory is supplied by bilateral motor cortices Lower facial territory is supplied only by contralateral motor cortex Therefore, unilateral central lesions spare upper face Lesions distal to geniculate ganglion ○ Mostly motor abnormalities Lesions proximal to geniculate ganglion ○ Motor, gustatory & autonomic abnormalities FAKULTAS KEDOKTERAN Vestibulocochlear Nerve The Vestibular Nerve for equilibrium/balance& posture) arises from the vestibular(scarpa’s) ganglion that is located at the bottom of the internal acoustic meatus. The Cochlear Nerve: for hearing arises from cells in the spiral (cochlear) ganglion in the organ of Corti.  VESTIBULOCOCHLEAR NERVE Special Sensory: Auditory/Balance VIII VestibuloCochlear is attached to the brain between the pons and medulla (at the cerebellopontine angle together with the Facial nerve) Vestibulocochlear & Facial nerve enters the internal acoustic meatus in the petrous temporal bone to the inner ear (organ of Corti & semicircular canal) Central afferent pathway of Vestibulocochlear nerve  Lesion of Vestibulocochlear Nerve Acoustic neuroma ; tumour of the schwann cells of 8th Cranial nerve Signs and symptoms: - dizziness (vertigo) & deafness; -progressive hearing loss, noises in the ear, involuntary rapid eye movement (nystagmus) -S/S compression on V& VII cranial nerves at cerebellopontine angle ---9,10,11 near jugular foramen Cranial Nerve attachments to the inferior aspect of the Brain GLOSSOPHARYNGEAL IX VAGUS X ACCESSORY XI Cranial Nerve Nuclei & Functional Components FAKULTAS KEDOKTERAN GLOSSOPHARYNGEAL Jugular Foramen-Exit together with 10 & 11 CN Functional Components : Motor fibers to stylopharyngeus (GSE) Sensory fibers –for general sensation and taste of the posterior 1/3 of the tongue & mucous membrane of the pharynx,tonsil and soft palate (GSA),(SSA) Carotid sinus and body-chemoreceptor & baroreceptor -influence blood pressure & respiration (SVA) Parasympathetic to parotid salivary gland thru otic ganglion (GVE) ○ Assist swallowing & salivation, conducts sensation from posterior part of tongue & pharynx (gag reflex) FAKULTAS KEDOKTERAN VAGUS NERVE (10th) Cranial Nerve Emerges from the upper part of medulla by rootlets between the olive & inferior cerebellar peduncle Leaves the posterior cranial fossa through the central part of Jugular foramen 2 ganglia-superior vagal & inferior vagal sensory ganglia FAKULTAS KEDOKTERAN Functional Components of Vagus 1.GSA-Auricular branch (external ear) 2. SVE- branchial motor component Pharyngeal branch to pharyngeal plexus provides voluntary control of ○ muscles of the pharynx and larynx, ( except for the stylopharyngeus muscle (CN IX) and the tensor veli palatini muscle (CN V).) ○ Palatoglossus muscle of the tongue ○ (the rest of the muscles of the tongue are innervated by CN XII). 3.Parasympathetic component GVE 4.Taste-from the root of the tongue FAKULTAS KEDOKTERAN Parasympathetic Components of Vagus Nerve (GVE) Cardiac branches Esophageal plexus Anterior vagal trunk (to anterior stomach and liver) Posterior vagal trunk (to posterior stomach) Celiac plexus (liver, kidney, small intestine, large intestine up to the splenic flexure)—secretomotor to smooth muscles and glands FAKULTAS KEDOKTERAN ACCESSORY NERVE-11th CN Cranial root joins the vagus and its branches are distributed to the muscles of soft palate and pharynx via pharyngeal plexus and to the muscles of larynx except the cricothyroid muscle –(responsible for movement of the soft palate,pharynx,larynx) Spinal root (from upper 5 cervical segments ascends along the spinal cord & enters the foramen magnum)- supplies the sternocleidomastoid and trapezius muscles FAKULTAS KEDOKTERAN HYPOGLOSSAL NERVE-XII Cranial Nerve Is a motor nerve Emerges from the medulla oblongata between the pyramid & olive Crosses the posterior cranial fossa & leaves the skull through the hypoglossal canal Passes downwards forwards to supply the tongue muscles except the palatoglossus Controls the shape & movement of the tongue FAKULTAS KEDOKTERAN NERVE LESIONS 9th,10th &11th Cranial Nerves can be compressed by a tumor while passing through the jugular foramen or the nuclei can be damaged in vascular lesions-(bulbar palsy, jugular foramen syndrome) Glossopharyngeal nerve lesion results in- Difficulty in swallowing, ○ loss of taste in posterior 1/3 of tongue ○ decrease salivation (parotid gland—otic ganglion) Vagus nerve lesion results in ○ hoarseness of voice due to paralysis of vocal cords ○ dysphagia-difficulty in swallowing Innervation of the tongue by various Cranial nerves FAKULTAS KEDOKTERAN NERVE LESIONS 2 Accessory nerve lesion ○ drooping shoulders ○ inability to rotate the neck (wry neck) ○ Difficulty in raising the shoulder and arm vertically Hypoglossal nerve lesion ○ moderate difficulty in speaking & chewing ○ dysphagia ○ tongue deviates to the side of lesion when protruded 10th/11th Cranial Nerve Palsy-uvula pulls towards the normal side-AHH! Test for motor innervation of soft palate  12th Cranial Nerve Palsy -tongue deviates towards the side of lesion due to unopposed action of the normal half Right hypoglossal lesion Left hypoglossal lesion