Neuro test 3

• in trochlear nucleus (inferior colliculus)
• decusate to form nerve
• innervate superior oblique M (depress eye)

• trouble keeping eye in down and inward position
• ex: while walking down stairs

• in abducens nucleus in lower pons (facial colliculus in rhomboid fossa)
• innervate ipsilateral lateral rectus M (abduction)

• flaccid paralysis of ipsilateral lateral rectus
• inable to abduct eye
• medial strabismus
• double vision- diplopia

• originates from oculomotor nuclear complex (midbrain- superior colliculus)
• edinger-westphal nucleus (autonomic, preganglionic parasympathetic fibers)
• E-W neurons terminate in ciliary ganglion

• constrictor pupillae M
• cilliary Ms

• superior rectus
• inferior rectus
• medial rectus
• inferior oblique
• levator palpebra superioris

• contraction of BOTH pupils due to increased light on a single retina
• afferent limb: II N thru optic tract and superior brachium to pretechtal nucleus to E-W nucleus
• efferent limb: E-W nucleus to ciliary ganglia to constrictor pupilla
• has both direct and consensual response

• shifing fron distant to near target
• requires convergence, accommodation, and pupillary constriction of both eyes by III N

retinal fibers to occipital lobe to superior colliculus to either occulomotor nucleus of III N or E-W nucleus of III N

these then innervate medial rectus (convergence), ciliary M (accommodation), and constrictor pupillae (pupillary constriction)

• unilateral lesion would cause:
• 1. ipsilateral paralysis of Ms causing droopy eyelid (ptosis) and lateral strabismus
• 2. no papillary light reflex
• 3. no accommodation reflex

• caused by loss of blood to anterior midbrain
• lesion of basal part of cerebral peduncle
• interupts oculomotor (III) N and descending motor fibers of cerebral crus
• RESULT: III N lesion, contralateral spastic hemiplegia

• originate from trigeminal motor nucleus (upper pons)
• bilateral innervation to:
• 1. Ms of mastication
• 2. tensor veli palatini
• 3. tensor tympani
• 4. mylohyoid
• 5. anterior belly of digastric

• flaccid paralysis
• deviation of the mandible towards the side of paralysis

• in geniculate ganglion
• innervate skin of external ear, wall of external auditory canal, external surface of tympanic membrane

spinalV tract to spinalV nucleus to Vthalamic tract to VPM thru posterior limb of internal capsule to primary S-S cortex

• in geniculate ganglion
• to taste r/c of anterior 2/3 of tongue and palate

solitary nucleus (in medulla) thru central tegmental tract (CTT) to VPM to postcentral gyrus and insula

• in facial nucleus in pons (traverse facial colliculus)
• innervate: Ms of facial expression, stapedius, posterior belly of digastric, and stylohyoid

• corticobulbar fibers
• bilateral to upper 1/2 of face
• unilateral to lower contralateral 1/2 of face
• auditory reflex for loud noise
• somatosensory input from trigeminal N
• causes corneal (blink) reflex

• touching the cornea causes bilateral blinking
• afferent limb- V N
• efferent limb- motor fibers of VII N
• direct and consensual respons

• superior salavitory nucleus
• postganglionic fibers thru submandibular gangion to submandibular gland, lingual gland, sublinqual gland, and labial glands
• secretomotor
• lacrimal nucleus
• from pterygopalatine gangia to lacrimal, nasal, and palatine glands
• secretomotor

• Bell's palsy
• -paralysis of all ipsilateral Ms innervated by facial N
• -loss of taste from ipsilateral anterior 2/3 of tongue and palate
• -decreased salivation
• -decreased lacrimation
• recovery is often fast

• in superior ganglion of IX N
• innervate: posterior 1/3 of tongue, upper pharynx, tympanic cavity, eustachian tube

spinalV tract to spinalV nucleus to Vthalamic tract to VPM to primary S-S cortex

• afferent limb- IX N
• efferent limb- X N, XII N, and V N
• touching posterior 1/3 of tongue/pharynx causes gaging

• in inferior ganglion of IX N
• thru lingual br of IX N to posterior 1/3 of tongue to solitary nucleus (in medulla) thru CTT to VPM to parietal lobe and insula

• in inferior ganglion of IX N
• to r/c in carotid sinus and carotid body to solitary tract to solitary nucleus to visceral centers in the reticular formation

• in nucleus ambiguus (medulla)
• innervate stylopharyngeus
• bilaterally innervated

• in inferior salavitory nucleus to otic gangion
• secretomotor for parotid gland

• rare
• loss of gag reflex from ipsilateral tongue
• decrease taste from posterior tongue
• decrease salivation

• in superior gangion of X N
• innervate: skin of external ear, lower pharynx, larynx, upper esophagus, external auditory canal

spinal V tract to spinal V nucleus to V thalamic tract to VPM to primary S-S cortex

• in inferior ganglion of X N
• to taste receptors on epiglottis

solitary nucleus thru CTT to VPM to paietal and insulal lobes

• in inferior ganglion of X N
• aortic arch baro and chemo r/cs, and distension of hollow organs thru the solitary tract to the solitary nucleus

• in the nucleus ambiguus
• forms the Vagus N and cranial root of XI N (to palate and larynx)
• innervates: all palate Ms except tensor veli palatini, all pharynx Ms except stylopharyngeus, all intrinsic larynx Ms, upper esophagus
• bilateral corticobulbar innervation

in dorsal motor nucleus of X N (medulla) to terminal/intramural ganglion near organs to visceral effector cells

• unilateral
• ipsilateral paralysis
• horseness of voice
• difficulty breathing
• difficulty swallowing
• uvula deviates away from lesioned side
• bilateral
• death from vocal folds adducting together

• in spinal accessory nucleus (C1-5)
• enters cranial vault thru foramen magnum
• joins cranial root prior to exiting jugular foramen (then cranial root joins with X N)
• to SCM and trap

unilateral lesion would cause ipsilateral paralysis of SCM and trap

• in hypoglossal nucleus in medulla
• innervates Ms of tongue except palatoglossus M
• contralateral innervation

unilateral lesion: ipsilateral paralysis of tongue, tongue would deviate toward lesioned side

• core of white matter
• projection, commissural, and association fibers

• thru internal capsule
• connect cerbrum to outside structure
• corticopedal fibers- into cerebrum
• corticofugal fibers- out of cerebrum

• connect the 2 hemispheres
• corpus callosum

• in a single hemisphere
• superior longitudinal fasciculus (connects motor and sensory language areas)

• 6 layers
• found in association areas

5 layers, found in uncus (olfactory areas)

3 layers, found in hippocampus

• mainly pyramidal cells
• giant pyramidal cells (BETZ cells) found in precentral gyrus
• stellate cells
• fusiform cells

layers 1-4

layer 4

primary sensory cortical areas

layers 5-6

• frontal lobe areas not involved in motor activity
• involved in: abstract thinking, descion making, judgement, behavior, reaction to experiances

• causes difficulty making good descions
• laxidasical behavior
• dishonesty

• language has a dominat hemisphere (usually left)
• lesion would cause aphasia (loss of language)

• opercular and triangular portions of inferior frontal gyrus
• -44 and 45
• motor area of language (speech, writing, and signing)

• posterior auditory association cortex (Wernicke's area)
• supramarginal and angular gyrus
• allows interpretation os language

• impaired ability to speak fluently
• can comprehend language, trouble responding

• inability to comprehend language
• con spontaneously speak, cant correct mistakes

• good comprehesion
• spontaneous speach
• unable to correct mistakes
• poor repetition, response to questions, reading out loud

• brach of vertebral As
• descend near dorsal lateral sulcus
• lie in subarachnoid space

• 2 braches off vertebral As- fuse together
• descends along ventral median fissure

• in pia mater around cord
• supplied by spinal As
• sulcal branches- enter cord thru ventral median fissure
• penetrating branches- to peripheral cord

anterior 2/3 of the cord

posterior 1/3 of cord

• replenish the blood in spinal As as they descend the cord
• enter thru IVF
• anterior radicular to anterior spinal A (9-12)
• posterior radicular to posterior spinal As (12-14)
• most vulnerable cord segments to occlusion- T1-4, L1

• give of medullary branches
• occlusions cause:
• lateral medullary syndrome (Wallenburg's syndrome)
• -loss of pain and temp from contralateral body
• -loss of pain and temp from ipsilateral face

formed from the fusing of the two vertebral As

to cerebellum

• thru internal auditory meatus to inner ear
• occlusions would cause ipsilateral deafness

to basilar pons

to cerebellum and superior cerebellar peduncles

• terminal br of basilar A
• lesion would cause cortical blindness of contralateral visual field

many branches, anatomoses with basilar A thru posterior communicating As

to pituitary gland

to eyeball and orbit

• to uncus, amygdala, and optic tract
• occlusion would cause contralateral hemianopsia

• to corpus callosum
• cingulate gyrus
• frontal and parietal gyrus
• orbial gyrus
• olfactory bulb and tract
• paracentral lobule
• lesions would cause contralateral spastic paralysis of lower extremities

• largest branch
• thru lateral sulcus to lenticulostriate As
• to auditory cortex
• motor cortex
• premotor- frontal eye field
• primary somatosensory
• dominant language area