Exam 3 Anatomy Memorization Flashcards
what cells are founding the molecular layer of the cerebellum
basket and stellate cells
what is the only excitatory neuron in the cerebellum
granule cells
what region bypasses the deep cerebellar nuclei and leaves from the inferior peduncle
vestibulocerebellum
vestibular neuritis
severe vertigo, nausea, vomiting but no hearing loss
Benign paroxysmal positional vertigo
brief vertigo episodes with changes in body position due to otoconia crystals lodged in the cupula of the semicircular canal
what synapses at the nucleus dorsalis of clark
1st order neurons of the posterior spinocerebellar tract ascending in the gracile fasciculus
superior cerebellar peduncle function
efferent route from globose, emboliform, and dentate nuclei
afferent from anterior spinocerebellar tract
middle cerebellar peduncle function
largest and carries afferent fibers from the pontine nuclei up to the cortex
inferior cerebellar peduncle function
afferent pathways from the spinal cord (posterior spinocerebellar and cuneocerebellar)
what afferents innervate receptor cells in the vestibular organ
vestibular ganglion or Scarpa ganglion
disruption of normal endolymph volume leading to endolymphatic hydrops
Meniere’s Disease
what route do vestibular afferents take
enter at PMJ, traverse the restiform body (inferior cerebellar peduncle) and branch to ascending and descending fibers
where do afferents from the semicircular canals (ampulla) generally project to
superior and medial vestibular nuclei
where do afferents from the otolith organs (maculae) generally project to
lateral, medial, and inferior vestibular nuclei
where do saccular afferents project to
contralateral oculomotor nucleus and influence vertical eye movements
area 2v and 3a
primary somatosensory cortex
area 7
parietal cortex for spatial orientation
insular areas of lateral sulcus and the parietoinsular vestibular Cortex (PIVC)
cells respond to body motion; lesions lead to vertigo and loss of perception for visual vertical
prefrontal cortex and superior frontal gyrus
vestibular eye signals related to frontal eye field
where is the object of attention focused and centered to in the retina
fovea centralis and macula lutea
optic disc is medial to macula lutea
Magnocellular layers of the LGN
layers 1 and 2; with large rod inputs that have large receptive fields; rapidly conducting for moving objects
Parvocellular layers of LGN
layers 3-6; small cone input with small receptive fields; stationary stimuli with high acuity
temporal retina axons terminate where
2, 3, and 5 of LGN ipsilaterally
nasal retina axons terminate where
1, 4, and 6 of LGN contralterally
where do fibers from the lower quadrant of contralateral hemifields originate and target
Dorsomedial LGN; through retrolenticular limb of IC and target superior bank of calcarine sulcus on the cuneus
where do fibers from upper quadrant of contralateral hemifields originate and target
ventrolateral LGN; arch up into white matter of temporal lobe making Meyer loop and target inferior bank of calacarine sulcus on the lingual gyrus
area 17
primary visual cortex
areas 18 and 19
visual association cortex; in parieto-occipitaq-temporal area
what spatial directs head/eye movements and visual reflexes (brainstem)
superior colliculus
what area is important for the pupillary light reflex
pretectal area
most likely areas for congruous lesions
posterior near cortex
associative visual agnosia
damage to left occipital lobe and posterior corpus callosum; leads to patient not being able to name or describe an object but can still use it
composition of the striatum
caudate - eye movement
putamen - motor
lenticular nucleus composition
putamen
globus pallidus - main output
what joins to form the thalamic fasciculus and enters the thalamus
lenticular fasciculus (through posterior limb of IC) ansa lenticularis (under post limb of IC)
Parkinson Disease
neurons from substantial migration do not release enough dopamine; leads to tremor, rigidity, and problems moving
Hypokinetic disorders
too little direct pathway and too much indirect pathway
hypokinesia and akinesis
Huntington’s disease
AD disorder leading to degeneration of neurons in the striatum and cerebral cortex leading to decreased GABA; trouble maintaining tongue protrusion and random flailing and jerky movements
hyperkinetic disorder
too little indirect pathway effects
athetosis
cannot sustain body part in one position
ballismus
flailing of entire extremity; contralateral subthalamic nucleus lesion
dystonia
persistence of posture at an extreme of an athetoid movement
where are the cell bodies of the cochlear part of CN 8
spiral ganglion; enter brainstem at PMJ and divide to ascending and descending branches before synapsing on cochlear nuclei
where do ascending bundles of the cochlear nerve synapse
anterior ventral cochlear nucleus
where do descending bundles of the cochlear nerve synapse
posterior division of the ventral cochlear nucleus and the dorsal cochlear nucleus
function of dorsal cochlear nucleus
identifying sound source elevation and complex characteristics
function of the ventral cochlear nucleus
horizontal localization of sound; anterior and posterior divisions
blood supply to the cochlea and auditory nuclei of the pons and medulla
basilar artery
blood supply of the inner ear and cochlear nuclei
labyrinthine artery off of the AICA
what does occlusion of AICA result in
monaural hearing loss along with ipsilateral facial palsy and inability to look towards the side of the lesion
blood supply of superior olivary complex and lateral lemniscus
short circumferential branches of the basilar artery
blood supply of the inferior colliculus
superior cerebellar and quadrigeminal
blood supply of medial geniculate bodies
thalamogeniculate arteries
blood supply of primary auditory and association cortices
M2 segment of middle cerebral artery
Wernicke’s area
comprehension of written and spoken language
Broca’s area
instruction for language output, planning movements to speak, and grammatical function of words
Area analogous to Wernicke’s
nonverbal signs from people interpretation
area analogous to Broca’s
instructions to produce non verbal communication (emotion gestures)
dorsal premotor cortex function in speech
motor programs for articulation
arcuate fasciculus function
word repetition
lateral temporal cortex function
semantic knowledge and word recognition or meaning
Broca area function
word processing, grammar, word production, and articulation
Wernicke area function
word representation and word retrieval
auditory agnosia
inability to describe a sound that has been heard; must be a sensory association cortex lesion bilaterally
global aphasia
non-fluent lesion of lateral sulcus leading to problems reading, writing, and speaking and understanding
Transcortical aphasia
similar to wernicke’s where they cannot understand but can still repeat; damage at the ACA/MCA border
Conduction aphasia
lesion of the supra marginal gyrus and arcuate fasciciulus; cannot repeat but fluency is intact
where do the frontal eye fields and superior colliculus project to in the saccadic horizontal system
paramedian pontine reticular formation (PPRF) or the horizontal gaze center CONTRALATERALLY
where do the axons travel to in the saccadic system after the PPRF
ipsilaterally (after initial crossing) abducens nucleus and crosses back to the original side in the MLF to the oculomotor nucleus
where do the frontal eye fields and superior colliculus project to in the saccadic vertical system
rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF) or the vertical gaze center
lesion at red nucleus
cannot look down
lesion at riMLF
cannot look up
nucleus prepositus hypoglossi
found in pons
tonic cells for locking on in the horizontal saccadic system
interstitial nucleus of cajal
found in midbrain
tonic cells for locking on in the vertical saccadic system
ominpause cells of the Raphe nuclei
found in the RF
inhibit burst neurons so no more neuronal firing in saccadic system
smooth pursuit pathway
parieto-occipital junction pontine nuclei in pons CONTRALATERAL vestibulocerebellum (flocconodular lobe) medial vestibular nuclei cross back to abducens nucleus cross to other side oculomotor nucleus
lesion of parietal lobe leads to
loss of smooth pursuit movements towards the side of the lesion
no optokinetic nystagmus when tape is moved towards damaged lobe
internuclear ophthalmoplegia (INO)
impaired horizontal eye movements
weak adduction of affected eye
abduction nystagmus of contralateral eye
due to lesion in MLF of the pons or midbrain
what part of the brainstem is responsible for the baroreceptor reflex
rostral ventrolateral medulla
Central or pre-ganglionic lesion in horners syndrome
anhidrosis
pupil dilates to drugs that cause NOR release
no response to alpha-agonists
before cervical ganglion
post-ganglionic lesion in Horner’s syndrome
normal sweating
no pupil dilation to drugs causing NOR release
pupil dilates to alpha-agonists
superior cervical ganglion or cavernous sinus lesion
what is in charge of the voluntary control of micturition
medial frontal cortex which sends inhibitory signals to inhibit the pontine micturition center
spastic bladder
lesions of pontine micturition center and sacral SC
often with MS
decreased bladder volume with increased pressure
basically contraction of detrusor and external sphincter are not coordinated
