module 12: brainstem and cerebellum

what is the brainstem composed of?

1. medulla oblongata

2. pons

3. midbrain

where is the medulla oblongata relative to the brain stem?

most inferior

what are pyramids? and what is their purpose?

they are white matter bulges that have descending tracts giving us control of skeletal muscles

what are descending tracts?

tracts that carry motor information from the brain to the spinal cord

what does decussation of pyramids mean? and how does it affect people?

• essentially its just a crossing of the pyramids - 90% cross

• it affects people because if you have a stroke in the left hemisphere of the brain your right side od the body will be affected

what do the olives do?

they relay muscle and joint position to the cerebellum - so the are involved in balance, coordination and also modulation of sound

what cranial nerves originate in the medulla oblongata

V, VII, IX, X, XI, XII

where is the pons relative to the brainstem

superior to the medulla but inferior to the midbrain

what sleep sections is the pons responsible for?

REM sleep cycle

what is the pontine nuclei responsible for?

communication between the cerebrum and cerebellum

what cranial nerves originate in the pons

V, VI, VII, VIII

where is the midbrain relative to the brain stem

most superior

what cranial nerves does the midbrain have?

III, IV, V

what are tectums?

its 4 mounds - each mound is known as a colliculi - there are 4 colliculi

what are the two superior colliculi responisble for?

for visual reflexes

wha are the two inferior collicui responsible for?

involved in hearing

what are the cerebellar peduncles?

3 nerve tracts

the superior cerebellar peduncle - carries axons from midbrain to the cerebellum

the middle cerebellar peduncle - carries information from the pons to th ecerebellum

the inferior cerebellar peduncle - carries information from the medulla to the cerebellum

what is the reticular formation? and whats it job?

a group of nuclei scattered throughout the brainstem - responsible for the sleep wake cycle (helps you stay awake)

where is the cerebellum located?

posterior to the brainstem - its actually attached to the brainstem

what is the arbor vitae?

tree shaped white matter axons that gather information from the gray matter and send to the brainstem

what are folia?

they are folds in the gray matter

what does the primary fissure do in the cerebellum?

separates the anterior and posterior lobes of the cerebeullum

what does the vermis do?

it separates the the lateral hemispheres

what is the flocculonodular lobe involved in?

balance - using environment to main the balance

what is the vermis invloved in?

gross motor coordination (walking) and fine motor coordination (moving the hand)

what are the cerebellar lateral hemispheres involved in?

fine motor coordination (moving the hand)