Flashcards in Brainstem Deck (41):
The inferior olivary nucleus projects solely to what through what
inferior cerebellar peduncle
What are the two components of the inferior cerebellar peduncle and their relative size?
juxtarestiform body (smaller)
restiform body (larger)
Where are the second order neurons in the medial lemniscal system?
NC & NG
The hypoglossal trigone lies over what nucleus?
The vagal trigone lies over what nucleus?
What is underneath the facial colliculus?
Genu of the facial nerve
What is underenat the vestibular area?
The remnants of the sulcus limitans lies between
the facial colliculus and the vestibular area
All cranial nerve nuclei are arranged within the brainstem medially-laterally as (general functions):
motor, somatomotor, automatic motor, sensory
Which three cranial nerves arise at ponto-medullary junction?
VI, VII, VIII
The medial 3/5ths of the basis pedunculi consist of what fibres?The other 2/5ths of the basis pedunculi consist of what fibres?
3/5th descending fibres of the corticospinal tract
2/5th corticopontine fibres
What is the function of the superior colliculus
integrates visual information for execution of visual reflexes
What is the function of the inferior colliculus?
associated with the auditory system
is part of the pathway which conveys information about hearing, speech, other auditory information
What does the superior cerebellar peduncle do?
Relay information OUT of cerebellum
What muscles are innervated by CN III?
CN II goes directly into what area of the brain
diencephalon (visual pathway)
What is the interpeduncular fossa?
depression between basis pedunculi
What three nuclei are associated with the inferior olive?
large principal olivary nucleus
smaller and older dorsal accessory and medial accessory olivary nuclei
What are the cells of origin for the medial lemniscus?
nucleus gracilis and nucleus cuneatus
What is the inferior salivatory nucleus?
Associated with medulla
Parasympathetic preganglionic outflow via CN IX
Goes to parotid gland
What cranial nerves exit at the ponto-medullary junction?
VI, VII, VIII
How many nuclear groups are associated with the trigeminal nerve? How many sensory? How many motor?
3 -s ensory
1 - motor
At what level of the brainstem do the corticospinal tracts stop being somatotopically organized?
caudal basilar pons
How is the corticospinal tract somatotopically organized?
neck fibres - medial
lower limb fibers - lateral
What types of structures are included in the pontine tegmentum?
cranial nerve related structures
What types of structures are included in the basilar pons?
some cerebellar related structures
Describe the path of the corticospinal pathway starting at the cortex
cortex --> internal capsule --> basis pedunculi --> basilar pons --> pyramidal tract
Describe the ascending medial lemniscal pathway from 1st order neuron to cortex
psueounipolar neuron in DRG --> medial bundle of dorsal root --> FC & FG --> NC & NG --> internal arcuate fibres --> sensory decussation --> medial lemniscus --> VPL --> somatosensory cortex
What cranial nerves contribute to the solitary tract and nucleus? What type of information do they carry? What ganglia do they involve?
CN VIII - taste from anterior 2/3 tongue - geniculate ganglion
CN IX - taste from posterior 1/3 tongue - chemoreceptor input from carotids - general visceral sensation - inferior ganglion
CN X - baroreceptor info from aortics - general visceral sensation - nodose ganglion
What information does the solitary tract & nucleus carry?
What is included in the vestibular apparatus?
semicircular canals, ampullae, utricle, saccule
What vestibular nuclei are found in upper medulla? In caudal pons?
Medial & inferior - upper medulla
Superior & lateral - caudal pons
What cranial nerves contribute to the spinal tract of trigeminal nerve? What ganglia do they involve?
CN V - semilunar ganglion
CN VII - geniculate ganglion
CN IX - superior ganglion
CN X - jugular ganglion
Describe the path of the cortico-pontine-cerebellar pathway. WHat fibres are involved? Where do they synapse?
frontal, occipital parietal regions of cortex --> basilar pons (synapse in pontine nuclei) --> MCP --> cerebellum
transverse fibres of pons
What is the trapezoid body?
crossing fibres of auditory pathway
cochlear division of CN VIII (conveys information related to hearing)
What are the muscles of mastication innervated by the motor nucleus of the trigeminal?
medial & lateral pterygoid
anterior belly of digastric
What information is carried in each of the four trigeminal nuclei?
principal sensory nucleus - fine touch
spinal nucleus - pain & temp
mesencephalic nucleus - proprio
motor nucleus - muscles of mastication
Which nucleus associated with control of extra-ocular muscles also has a parasympathetic component which influences smooth muscles in the eyeball?
Why does the pars compacta appear pigemented?
neurons of pars compacta are dopaminergic and metabolism of dopamine produces melanin why pars compacta has pigemented appearance
Where are we likely to lose somatotopy in the descending corticospinal tracts?
At the level of the basilar pons