Brainstem and cranial nerves Flashcards
How many of the cranial nerves are connected to the brainstem?
10 of 12
What are the three parts of the brainstem?
Midbrain
Pons
Medulla
What is the crus cerebri?
A bundle of fibres that connects the cerebral cortex and the brainstem
What is the middle cerebellar peduncle?
A bundle of fibres that connects the cerebellum and brainstem
Where is the inferior colliculus (auditory)?
A hillock on the dorsal surface of the midbrain
Where is the superior colliculus (visual)?
Posterior surface of brainstem
Where are the olives/inferior olivary nuclei?
Latero-ventral surface of the medulla
Where are the pyramids found?
Above the olives
Which cranial nerve is the only one to exit on the dorsal side?
Trochlear nerve
Where are the superior and inferior peduncles visible?
Posterior surface of the brainstem
Where are the mamillary bodies?
Belong to hypothalamus (not part of brainstem)
Which cranial nerves are for the special senses?
1, 2 and 8
Which cranial nerves do not attach to the brainstem?
1 and 2
What is cranial nerve 1?
Olfactory tract
What is cranial nerve 2?
Optic nerve
Where does the optic nerve become the optic tract?
Posterior to the optic chiasm (between optic chiasm and LGN)
Describe the path of light from the lateral visual field to the LGN.
Reaches nasal part of retina
Neurons cross in the optic chiasm so they end up synapsing with the LGN on the contralateral side
Describe the path of light from the contralateral visual field to the LGN.
Reaches temporal part of retina
Axons do not cross in the optic chiasm so they end up in the ipsilateral LGN
What is the 8th cranial nerve?
Vestibulocochlear nerve
What does the vestibulocochlear nerve do?
Mediates balance and hearing
Where are the vestibulocochlear nuclei found?
Lateral recesses of the 4th ventricle
Which cranial nerves move the eyeball?
3, 4 and 6
What is the 3rd cranial nerve?
Oculomotor nerve
What is the 4th cranial nerve?
Trochlear nerve
What is the 6th cranial nerve?
Abducens nerve
Which 2 nuclei does the oculomotor nerve originate from?
Edinger-Westphal nucleus
Oculomotor nucleus
(Both at level of superior colliculi)