Brainstem 1 Flashcards
What is the function of the brainstem?
- Compact, stalklike structure that carries nearly all information between the brain and the remainder of the body
- Corridor to all major sensory, motor, cerebellar, and cranial nerve pathways.
- Not simply a conduit for information. It also contains numerous important nuclei of its own, which control the cranial nerves; level of consciousness; cerebellar circuits; muscle tone; posture; and cardiac, respiratory, and numerous other essential functions
What 3 structures make up the brainstem?
Midbrain
Pons
Medulla
The facial colliculi is formed by what 2 structures?
abducens nuclei
fibers of the facial nerve
What structures are in the hypoglossal trigone and vagal trigone?
The hypoglossal trigone and vagal trigone are formed by the hypoglossal nucleus (CN XII) and the dorsal motor nucleus of CN X, respectively
Describe how the 4th ventricle drains into the subarachnoid space.
The fourth ventricle drains into the subarachnoid space via the foramina of Luschka (located laterally) and foramen of Magendie (located in the midline)
What is the Obex?
- The end point of the fourth ventricle
- Marks the entry to the spinal cord central canal, which in adults is normally closed
- What section of the medulla is this (inferior, middle, superior)?
- How can you tell?
- What landmarks identify this as a section of the medulla?
- Inferior
- Pyramidal decussation visible in lower medulla
- Pyramidal decussation, posterior columns mostly white matter than grey (become more grey as move up in medulla to where nuclei are)
- What section of the medulla is this (inferior, middle, superior)?
- How can you tell?
- What landmarks identify this as a section of the medulla?
- Middle
- Pyramids visible, only happens after crossing at pyramidal decussation which is in inferior medulla
- Pyramids, butterfly shape of white matter on sides
- What section of the medulla is this (inferior, middle, superior)?
- How can you tell?
- What landmarks identify this as a section of the medulla?
- Superior
- 4th ventricle is starting to be visible, only visible in superior medulla
- 4th ventricle visible, inferior olive visible, pyramids, inferior cerebral peduncle
- What section of the pons is this (inferior, superior)?
- How can you tell?
- What landmarks identify this as a section of the pons?
- middle
- 4th ventricle is visible (it runs most of length of pons but not the most extreme parts superior and inferior
- 4th ventricle, middle cerebellar peduncle
- What section of the pons is this (inferior, superior)?
- How can you tell?
- What landmarks identify this as a section of the pons?
- Superior
- Cerebral aqueduct is visible (drains into 4th ventricle near top of pons)
- Cerebral aqueduct and the distinct shape and patterning of the pontine nuclei
- How can you tell this is a section of the midbrain?
- Label all structures.
- Cerebral aqueduct is rather small, superior cerebellar peduncle is visible, inferior colliculus is visible, cerebral peduncle is visible
The superior colliculus is important for […] while the inferior colliculus is important for […]
Orienting your eyes to important things that need your attention
Hearing
Reticular Formation
- What is this structure?
- Nuclei in the rostral reticular formation primarily perform what task?
- Nuclei in the caudal reticular formation primarily perform what task?
- A central core of nuclei that run through the entire length of the brainstem
- Alert conscious state
- Motor, reflex, and autonomic functions
