Brainstem- topography and weigerts Flashcards
What are the cerebral crura?
Two large motor bundles
What separates the two cerebral crura?
The interpeduncular fossa
What exits the midbrain via the interpeduncular fossa?
The occulomotor nerve
Where are the mammillary bodies located?
The interpeduncular fossa
What separates the crura from the tegmentum?
The substansia nigra
Where is the pretectum located?
Posterior to aqueduct but in front of tectum
What do the superior and inferior colliculi contain?
Relay nuclei for the visual and auditory nerve pathways
Where does the trochlear nerve exit the midbrain?
Posteriorly, below the inferior colliculus
Which cranial nerve exits from the dorsal aspect of the brainstem?
Trochlear nerve
What is the main linkage between the cerebrum and the cerebellum?
The pons
What connects the pons to the cerebrum?
The middle cerebellar peduncles
What is the anterior pons known as?
The basilar pons
What is the posterior pons known as?
The tegmentum
Where are the superior cerebellar peduncles located?
Lateral to the fourth ventricle
What exits the lateral pons?
The trigeminal nerve
What do the pyramids of the anterior medulla oblongata contain?
Pyramidal tracts that decussate in the most inferior part of the medulla
What are olives?
Ovoid ridges lateral to the pyramids in upper and middle medullas
Which nerves exit the brainstem at the pontomedullary junction?
Abducens (CNVI), facial (CNVII), vesitbulocochlear (CNVIII)
Which cranial nerves exit the upper medulla posterior to the olives?
Glossopharyngeal (CNIX), vagus (CNX), accessory (CNXI)
What do the middle of each crus contain?
Voluntary fibres
What do the medial and lateral fifths of each crura contain?
Involuntary fibres
Where do the superior cerebellar peduncles decussate?
The lower midbrain
Which nerve exits between the pyramids and the olives?
CN XII- hypoglossal
What do the inferior cerebellar peduncles link?
The medulla oblongata to the cerebellum
Where do the medial lemnisci decussate?
The medulla oblongata
What are the medial lemnisci formed from?
Axons of nucleus gracilis and nucleus cuneatus
Where do the pyramids decussate?
The lower medulla
