Intro into Brainstem Flashcards
If you see cerebral aquedeuct, what par tof brain are you in?
midbrain
if you see 4th ventricle, what part of brain are you in
pons/rostrol medulla (cerebellum behind)
if you see central canal, what part of brian are you in
caudal medulla
-continuous w/ the central canal of the cord
what is the tectum of the brainstem?
where is it located
what does it contian
lumpy, bumpy back of the midbrain
- in the midbrain, located behind the ventricular space (cerebral aqueduct)
- contains sup and inf colliiculi
what doe the tegmentum contain
where is it located in the pons/medulla? in the midbrain?
ascending long tracts
cranial nerve nuclei
reticular formation
- located in the floor of the ventricular spaces: floor of the 4th ventricle in the pons/medulla
- floor of the cerebral aqueduct in midbrain
what are the functions of the brainstem
transmission of motor and sensory info
control of cranial nerves (3-12)
control of breathing, heart rate, consciousness (RAS)
what happens to a lesion in the pyramidal, medial lemniscus, and spinothalamics tract in the brainstem? what about in the cord?
contral clinical deficits
where do afferent cranial nerve fibers start? what do they head towards
start in the periphery and head towards nuclei in the brainstem-they will enter the VENTRAL (usually) aspect of brainstem
where do efferent cranial nerve fibers start
start in the brainstem (in CN nuclei) and “exit” the VENTRAL (usually) brainstem towards the head or body
where does CN3 exit
the midbrain btwn the crus cerebri of the cerebral peduncles in the interpedunclar fossa
where does CN4 exit?
THE EXCEPTION-exits from the dorsal brainstem
where does CN 5 exit
exit/enters out laterally in the middle of the pons
where does CN 6, 7, 8 exit
pontomedullary junction
where does CN 9 and 10 exit
lateral medulla
where does CN 12 exit
btwn the pyramids and inf olive
cranial nerves exit…..
but the nuclei reside in…
the brainstem ventrally
dorsal tegmentum
what are the nerve fibers that columns of nuclei share
discontinuous columns of motor nuclei
continuous columns of sensory nuclei
what do cranial nerve nuclei do?
what do some cranial nerves
nucleus: subserves a single sensory or motor task (in column of similar function)
nerves: conveys many tasks (can use nuclei in multiple columns)
which are the mixed CN?
5, 7, 9, 10
which CN has an additional autonomic component (while still being motor)
CN3
what happens in lesions of the reticular formation in the lower brainstem?
fatal since it controls the cardiorespiratory centers (breathing, heart rate, bp)
lesions of the reticular formation in the midbrain cause what
coma
what is reticular formation in the midbrain
ascending sensory info to stimulate the cerebral cortex and maintain consciousness
-called reticular activating system (RAS)
what is reticular formation in the pons and medulla
vital centers for control and cardiac and respiratory
