Brainstem (Internal Anatomy) Flashcards
medulla oblongata connects the ____ superiorly and the ____ inferiorly
pons superiorly
cervical spinal cord inferiorly
continuous with anterior median fissure of SC
anterior median fissure of medulla oblongata
swelling on each side of median fissure
pyramids
pyramids are bound laterally by
ventrolateral sulcus
Pyramids carry ___ and ____ tracts to SC
lateral and anterior corticospinal tracts
pyramids carry ____ fibers in brainstem
corticobulbar fibers
emerge from the anterior median fissure and pass laterally over the surface of medulla to enter the cerebellum
anterior external arcuate fibers
anterior external arcuate fibers arise from arcuate nuclei at ____ and pass around the lateral surface to enter the ____
base of medulla, inferior cerebellar peduncle
posterolateral to the pyramids
oval elevations produced by underlying inferior olivary nuclei
olives
rootlets of ____ emerge from the groove between the pyramds and olives
hypoglossal nerve
posterior to the olives; connect medulla to cerebellum
inferior cerebellar peduncles
roots of ______, _____ and rootlets of ______ emerge lateral to the olives
glossopharyngeal, vagus
rootlets of accessory nerves
part of medulla oblongata that forms the lower part of the floor of the 4th ventricle
posterior surface of the superior half of the medulla
sulcus found in the posterior surface of the inferior half of the medulla
posterior median sulcus
what do you find on each side of posterior median sulcus
gracile tubercle
lateral to the gracile tubercle
cuneate tubercle
level of pyramidal decussation somatotopically organized
LE more lateral
UE medial
corticospinal fibers that convey impulses to the neck and UE cross first
lateral corticospinal tract
levels of medulla
Caudal half: pyramidal decussation, decussation of lemnisci
Rostral half: level of olives, level just inferior to pons
superiorly, the ____ occupy and form the pyramid
corticospinal fibers
inferiorly, about 90% of the corticospinal fibers decussate and continue down the lateral funiculus as
lateral corticospinal tract
posterior extensions of the central gray matter
nucleus gracilis and nucleus cuneatus
becomes continuous with the inferior end of the nucleus of the spinal tract of trigeminal nerve
substantia gelatinosa
level of sensory decussation
level of lemnisci decussation
inferior half of medulla
crossing of second order neuron of the posterior column- medial lemniscus pathway
level of lemnisci decussation
decussation of lemnisci occurs ____ to the central gray matter, ____ to the pyramids
anterior to the central gray matter
posterior to the pyramids
axons of neurons in the dorsal column nuclei travel ventromedially as _____ and cross to the opposite side to form the ____
internal arcuate
medial lemniscus
dorsolateral position in medulla
lies lateral to the internal arcuate fibers
spinal nucleus of trigeminal nerve (spinal trigeminal nucleus)
spinal nucleus of trigeminal nerve descends to
c3 level of sc
sensations in spinal tract and nucleus of trigeminal nerve
exteroceptive sensations (pain, temp, light touch) from ipsilateral face
lateral to lemnisci decussation
lateral spinothalamic tract
anterior spinothalamic tract
spinotectal tract = spinal lemniscus
anterolateral region of lemnisci decussation
spinocerebellar tract
vestibulospinal tract
rubrospinal tract
oval elevations produced by underlying inferior olivary nuclei
olives
gray matter shaped like crumped bag with mouth directed medially
responsible for the olives
olivary nuclear complex
principal nucleus, medial accessory olivary nucleus and dorsal accessory olivary nucleus
inferior olivary nucleus
cells of the inferior olivary nucleus send fibers medially across the midline to enter the cerebellum through the
inferior cerebellar peduncle
afferent fibers of olivary nuclear complex
spino-olivary tracts, cerebellum, and cerebral cortex
olivary nuclear complex is associated with
voluntary muscle movement
Vestibular nuclear complex consists of
- medial vestibular nucleus
- inferior vestibular nucleus
- lateral vestibular nucleus
- superior vestibular nucleus
vestibular nuclear complex is seen at this level
medial and inferior
anterolateral aspect of the inferior cerebellar peduncle
anterior cochlear nucleus