Brain stem and cranial nerves Flashcards
What is the function of the cerebral peduncles?
They act as the main output from the cortex to either the spinal cortex or the main input to the pons
What is the function of the interpeduncular fossa
Can show subtle sub-arachnoid haemorrhages on CT scans
What is the function of the pons?
Acts as a bridge across the cerebellum
What is the function of the medulla oblongata
Contains the descending corticospinal pathway
How many pyramids are present on the medulla oblongata
2
Where are the olives (olivary nuclei) ?
On the medulla oblongata
What is the function of the olives?
There are olivary nuclei within the olives
What is present on the posterior aspect of the midbrain?
Superior and inferior colliculi
What is the function of the superior and inferior colliculi?
Superior: related to the visual system e.g. coordination of eye movement
Inferior: part of the auditory pathway
What is the name given to the superior and inferior colliculi together
Corporate quadrigeminy
What is the only cranial nerve that is from the posterior aspect of the brain stem
The fourth cranial nerve: Trochlear nerve
What are the types of cerebellar peduncles present
Superior/middle/inferior
What else is present on the posterior aspect of the brain stem
The floor of the fourth ventricle
What else is present on the floor of the fourth ventricle
The facial colliculi (called this as colliculi is close to the facial nerve). Can see lesions here
What is the median vesicular nucleus
Bundle of nerve fibres that allow communication between the nuclei that control the nerves for eye muscle movement
What is the forman of Megende
Allows CSF to flow out of the 4th ventricle
What is the forman of Luschka
Allows CSF to flow out of the 4th ventricle
Where do the olfactory nerves travel through (and exit)
The cribriform plate (going into the nasal mucosa)
How does the second cranial nerve exit the central skull base
Through the optic canal
What cranial nerves exit by the super orbital fissure
Oculomotor nerve/3rd/4th/5th
Where else can the 5th travel through
- ) The foramen of rotundum
2. ) The foramen of ovale
Key features of the first cranial nerve
- Supply the sensory mucosa over the nasal mucosa
- Cribriform plate separates the two olfactory bulbs (this bit is known as the crista galli)
Key features of the second cranial nerve
- Comes from the back of the retina
- involved in the optic chiasm (where half of the fibres cross over)
Key features of the third cranial nerve
- comes off the base of the cerebellar peduncles
- runs forwards to the wall of the cavernous sinus
