Brain stem and cranial nerves

Question 1

What is the function of the cerebral peduncles?

Answer 1

They act as the main output from the cortex to either the spinal cortex or the main input to the pons

Question 2

What is the function of the interpeduncular fossa

Answer 2

Can show subtle sub-arachnoid haemorrhages on CT scans

Question 3

What is the function of the pons?

Answer 3

Acts as a bridge across the cerebellum

Question 4

What is the function of the medulla oblongata

Answer 4

Contains the descending corticospinal pathway

Question 5

How many pyramids are present on the medulla oblongata

Answer 5

2

Question 6

Where are the olives (olivary nuclei) ?

Answer 6

On the medulla oblongata

Question 7

What is the function of the olives?

Answer 7

There are olivary nuclei within the olives

Question 8

What is present on the posterior aspect of the midbrain?

Answer 8

Superior and inferior colliculi

Question 9

What is the function of the superior and inferior colliculi?

Answer 9

Superior: related to the visual system e.g. coordination of eye movement
Inferior: part of the auditory pathway

Question 10

What is the name given to the superior and inferior colliculi together

Answer 10

Corporate quadrigeminy

Question 11

What is the only cranial nerve that is from the posterior aspect of the brain stem

Answer 11

The fourth cranial nerve: Trochlear nerve

Question 12

What are the types of cerebellar peduncles present

Answer 12

Superior/middle/inferior

Question 13

What else is present on the posterior aspect of the brain stem

Answer 13

The floor of the fourth ventricle

Question 14

What else is present on the floor of the fourth ventricle

Answer 14

The facial colliculi (called this as colliculi is close to the facial nerve). Can see lesions here

Question 15

What is the median vesicular nucleus

Answer 15

Bundle of nerve fibres that allow communication between the nuclei that control the nerves for eye muscle movement

Question 16

What is the forman of Megende

Answer 16

Allows CSF to flow out of the 4th ventricle

Question 17

What is the forman of Luschka

Answer 17

Allows CSF to flow out of the 4th ventricle

Question 18

Where do the olfactory nerves travel through (and exit)

Answer 18

The cribriform plate (going into the nasal mucosa)

Question 19

How does the second cranial nerve exit the central skull base

Answer 19

Through the optic canal

Question 20

What cranial nerves exit by the super orbital fissure

Answer 20

Oculomotor nerve/3rd/4th/5th

Question 21

Where else can the 5th travel through

Answer 21

1. ) The foramen of rotundum

2. ) The foramen of ovale

Question 22

Key features of the first cranial nerve

Answer 22

• Supply the sensory mucosa over the nasal mucosa

- Cribriform plate separates the two olfactory bulbs (this bit is known as the crista galli)

Question 23

Key features of the second cranial nerve

Answer 23

• Comes from the back of the retina

- involved in the optic chiasm (where half of the fibres cross over)

Question 24

Key features of the third cranial nerve

Answer 24

• comes off the base of the cerebellar peduncles

- runs forwards to the wall of the cavernous sinus