USAHS NEUROSCIENCE TEST #5
QUESTIONS WITH COMPLETE
SOLUTIONS
CN9: - ANSWER -Exits brainstem as several rootlets along the upper ventrolateral
medulla bw inferior olive and inferior cerebellar peduncle
CN10: - ANSWER -Exits ventrolateral medulla as several rootlets just below CN9 bw
inferior olive and inferior cerebellar peduncle
CN11: - ANSWER -Nerve rootlets leave nucleus and exit lateral aspect of SC bw dorsal
and ventral roots just dorsal to the dentate ligament and ascend through foramen
magnum
Hypo- hypoglossal foramen - ANSWER -Exits ventral medulla as multiple rootlets bw
pyramid and inferior olivary nucleus in hypoglossal foramen
Open medulla is
closed medulla is - ANSWER -dorsal/posterior with the four dots;
·ventral/anterior and will show the big belly of pons and pyramids with olives on either
side
Midbrain: - ANSWER -Inferior colliculi is hearing;
superior colliculi is vision
retinal blood supply= - ANSWER -ophthalmic artery
§ ophthalmic artery branches into retinal artery
§ blockages: emboli, stenosis, vasculitis
retinal artery - ANSWER -2 main branches: Superior, Inferior
Occlusion causes an altitudinal scotoma in one eye
· Ex- Pt would lose vision in lower half of R eye caused by occlusion of superior branch
of R retinal artery in R eye
Amaurosis fugax- transient occlusion of superior or inferior branch of retinal artery
· Vision "browning out" in either upper or lower part
· Lasts ~10 min
· Common cause: ipsilateral ICA stenosis (like a TIA)
· At risk for retinal or cerebral infarct
, Optic nerves, optic chiasm, optic tracts receive blood supply from numerous small
branches of ACA and MCA - ANSWER -Rarely see significant infarcts
Infarct here Won't have clinically significant impact
LGN has variable blood supply - ANSWER -Anterior choroidal branch (from ICA), PCA,
thalamogeniculate artery
Infarcts: see contralateral homonymous hemianopia
Optic radiations- - ANSWER -superior and inferior pass through diff lobes
Superiors= parietalà blood supply from superior MCA
· Infarct: contralateral inferior quadrantanopia
Inferior/Meyer's loop: temporal lobe àinferior MCA
· Infarct: contralateral superior quadrantanopia
Rostral reticular formation: Subcortical arousal systems - sleep-wake cycles - ANSWER
-Upper brainstem neurons
§ Norepinephrine, serotonin, dopamine
§ Project to cortical and subcortical forebrain
§ Norepinephrine and dopamine- alertness, mood elevation, working memory
Norepinephrine- - ANSWER -regulates sleep wake cycle
o Drugs enhance norepinephrine transmission to normalize sleep cycles
o Narcolepsy, adhd
dopamine - ANSWER -o Involved in controlling movement; Issues w reward and
addiction
o Parkinson's- lack of dopamine = hypokinetic mvmt and working memory deficits
serotonin - ANSWER -alertness, mood elevation, breathing control
· psychiatric syndromes
· Depression, anxiety, OCD, eating disorders
o Upper brainstem neurons and pontomesencphalic reticular formation neurons -
ANSWER -§ Acetylcholine- alertness, memory! Attention and memory learning
· Degeneration is one of main causes of Alzheimer's
§ glutamate
§ Project to thalamus, hypothalamus, basal forebrain
· Relay station of info, autonomic and homeostasis
QUESTIONS WITH COMPLETE
SOLUTIONS
CN9: - ANSWER -Exits brainstem as several rootlets along the upper ventrolateral
medulla bw inferior olive and inferior cerebellar peduncle
CN10: - ANSWER -Exits ventrolateral medulla as several rootlets just below CN9 bw
inferior olive and inferior cerebellar peduncle
CN11: - ANSWER -Nerve rootlets leave nucleus and exit lateral aspect of SC bw dorsal
and ventral roots just dorsal to the dentate ligament and ascend through foramen
magnum
Hypo- hypoglossal foramen - ANSWER -Exits ventral medulla as multiple rootlets bw
pyramid and inferior olivary nucleus in hypoglossal foramen
Open medulla is
closed medulla is - ANSWER -dorsal/posterior with the four dots;
·ventral/anterior and will show the big belly of pons and pyramids with olives on either
side
Midbrain: - ANSWER -Inferior colliculi is hearing;
superior colliculi is vision
retinal blood supply= - ANSWER -ophthalmic artery
§ ophthalmic artery branches into retinal artery
§ blockages: emboli, stenosis, vasculitis
retinal artery - ANSWER -2 main branches: Superior, Inferior
Occlusion causes an altitudinal scotoma in one eye
· Ex- Pt would lose vision in lower half of R eye caused by occlusion of superior branch
of R retinal artery in R eye
Amaurosis fugax- transient occlusion of superior or inferior branch of retinal artery
· Vision "browning out" in either upper or lower part
· Lasts ~10 min
· Common cause: ipsilateral ICA stenosis (like a TIA)
· At risk for retinal or cerebral infarct
, Optic nerves, optic chiasm, optic tracts receive blood supply from numerous small
branches of ACA and MCA - ANSWER -Rarely see significant infarcts
Infarct here Won't have clinically significant impact
LGN has variable blood supply - ANSWER -Anterior choroidal branch (from ICA), PCA,
thalamogeniculate artery
Infarcts: see contralateral homonymous hemianopia
Optic radiations- - ANSWER -superior and inferior pass through diff lobes
Superiors= parietalà blood supply from superior MCA
· Infarct: contralateral inferior quadrantanopia
Inferior/Meyer's loop: temporal lobe àinferior MCA
· Infarct: contralateral superior quadrantanopia
Rostral reticular formation: Subcortical arousal systems - sleep-wake cycles - ANSWER
-Upper brainstem neurons
§ Norepinephrine, serotonin, dopamine
§ Project to cortical and subcortical forebrain
§ Norepinephrine and dopamine- alertness, mood elevation, working memory
Norepinephrine- - ANSWER -regulates sleep wake cycle
o Drugs enhance norepinephrine transmission to normalize sleep cycles
o Narcolepsy, adhd
dopamine - ANSWER -o Involved in controlling movement; Issues w reward and
addiction
o Parkinson's- lack of dopamine = hypokinetic mvmt and working memory deficits
serotonin - ANSWER -alertness, mood elevation, breathing control
· psychiatric syndromes
· Depression, anxiety, OCD, eating disorders
o Upper brainstem neurons and pontomesencphalic reticular formation neurons -
ANSWER -§ Acetylcholine- alertness, memory! Attention and memory learning
· Degeneration is one of main causes of Alzheimer's
§ glutamate
§ Project to thalamus, hypothalamus, basal forebrain
· Relay station of info, autonomic and homeostasis
