Brainstem 1 Flashcards
what is in the brainstem (4 functional parts)
cranial nerve nuclei, long tracts, cerebellar circuits, reticular formation
lesion to long tract
produce sensory and motor deficits
lesion to cerebellar circuit
ataxia
medulla contains
long sensory tracts, motor tracts, cranial nerve nuclei, reticular formation, raphe nuclei, connections to cerebellum (olive)
pontine-cerebellar junction
CN 6, 7, 8
how do you recognize a section of medulla
the squiggles of the inferior olive
principal sensory nucleus
fine touch;
principal motor nucleus fxnl component
SVE; anterior digastric …etc. muscles of mastication
mesencephalic nucleus
proprioception from teeth and TMJ; pseudounipolar neurons that never made it out of the brain. this is the only place where that happens in the brain
where does CN 12 exit
between medullary pyramids and the olive
fibers of solitary nucleus
SVA (taste) GVA(carotid body, sinus)
dorsal motor vagal nucleus in medulla
GVE. (psy) as you go rostrally, it becomes the inferior salvitory nucleus
CN10 exits between
dorsal column and the olive
decussation of pyramids happens where
around C1 caudal medulla
tracts of brainstem
- pyramidal tract
- dorsal column system
- spinothalamic system (als)
pyramidal tract fibers
corticospinal and corticobulbar fibers
primary ascending tracts
med. lemniscus = somatosensory = ALS
lat. lemniscus = auditory
three cbellar connections
anterior spinocerebellar tract
corticopontine tract
olivocerebellar tract
where do dorsal columns of spinal cord synapse
GSA cuneate and gracile nuclei. dorsal columns are another name for the cuneate and gracile fasiculi
what does the substantia gelatinosa become
spinal trigeminal nucleus (pars caudalis)
medial lemniscus comes from
gracile and cuneate nuclei. it is somatotopically organized.
internal arcuate fibers
connect the gracile, cuneate nuclei to the medial lemniscus
C shaped axons around a nucleus is….
ALWAYS spinal trigeminal tract/nucleus
the nucleus is aka pars caudalis
the black donut in the medulla
solitary nucleus
restiform body
essentially the inf. cerebellar peduncle; primary fibers are from the dorsal and ventral spinocerebellar tracts
reticular formation divisions
medial zone (ascending is conciousness, descending is motor); raphe nuclei (pain); lateral zone (cranial nerve reflexes for respiration, BP, heart rate)
medullary blood vessels
vertebral aa.; PICA; anterior spinal arteries; posterior spinal arteries
inferior olive blood supply
vertebral artery. it also supplies the ALS
lateral medullary (wallenberg) syndrome lesion
PICA SYNDROME; lesion of pica
lateral medullary syndrome in medulla affects what fxnl areas (6)
spinal trigeminal (ipsilateral pain face);
ALS (contralateral pain body);
vestibular nuc (vertigo);
solitary nuc (ipsilateral taste loss);
DVN/ambiguus (hoarseness and dysphagia);
hypothalamospinal (mainly ipsilateral horners)
REVIEW: horner’s symptoms
meiosis, anhydrosis, ptosis
medial medullary infarct affects what 3 fxnl areas
medial lemniscus(contralat. loss of fine touch);
pyramids (contralat. hemiplegia);
hypoglossal n
lateral medullary syndrome in basilar pons
corticospinal/corticobulbar
abducens n (ipsilateral loss of abducens)
pyramidal (contralateral hemiplegia)
lateral medullary syndrome in basilar pons. this is one of three ___?
middle alternating hemiplegia; cranial nerve sign and a contralateral body paralysis
facial colliculus
bump where CN VII fibers are arching over CN VI
fibers from cbellum through the sup. cbellar peduncle go to
red nucleus, thalamus
hippocampus part of brainstem
NO. not at all.
a lobule of cerebellum contains?
folia
how many lobules of cbellum
10
how many layers in the cortex of cerebellum?
3; molecular, purkinge, granular cell layers
cbellum is intrinsically linked to?
vestibular system
4 functions of cbellum
precise dextrous mvmts; timing of muscle activation; motor memory; posture and balance
3 nuclei in cbellum
dentate, interposed, fastigial
3 cortex regions of cerebellum
cerebro-cbell, spino-cbell, vestibulo-cbell
what fiber bundle connects pons to cbellum
middle cbellar peduncle
important feature of pons
contains nuclei for hearing (ventral, dorsal cochlear nuc.)
trapezoid body is?
crossing fibers in pons of auditory system
lateral lemniscus sends fibers?
sends fibers that will surround and synapse with the inf. colliculus (auditory syst)
cerebro-cbellum is located?
in the big lateral part of the cbellum
flocculus and nodulus related to what system?
vestibular system of cbellum
lesions of the vermis produce?
profound postural and balance problems; look like they are drunk; ataxia
which lobules are in the anterior cbellar lobe?
I-V; VI to X are in the posterior cbellar lobe
how should you think about the cbellum?
a rectangle; medial parts project to medial nuclei, and lateral parts project to lateral nuclei
what is the shape of the medial lemniscus in the pons?
it points medio-laterally now. in the medulla, it points antero-posteriorly
what is a mossy fiber? synapse?
inputs to cbellum (other than those from the inferior olive) the mossy fibers synapse on the parallel fibers.
what is a parallel fiber?
axons of the granular cells
what is a climbing fiber?
inputs to cbellum from olive to inhibitory interneurons
what kind of output is purkinge?
these are GABAergic (inhibitory)
what kind of pathway is spino-cbellar
unconscious proprioception.
dysdiadochokinesia
characteristic of cbellar lesion; example of ataxia
result of fetal alcohol syndrome
kills purkinje cells especially in the vermis; often no corpus callosum
blood supply to cbellum
superior cerebellar artery (end of basilar a); AICA (basilar a); PICA (vertebral a.)
primary CNs of pons
V, VII, some VIII
spinal trigeminal tract receives facial sensory signals from which CNs
V, VII, IX, X
superior salvitory nucleus location? fxn?
GVE in pons. it is CN VII for submandibular glands, tears etc.
