Brainstem

Question 1

Where is the brainstem located?

Answer 1

In the posterior cranial fossa, extending from the mammillary bodies rostrally to the pyramidal decussation caudally

Question 2

What are the 3 areas of the brainstem?

Answer 2

Midbrain, pons, medulla

Question 3

What is the anatomy of the dorsal aspect of the midbrain?

Answer 3

Superior and inferior colliculi

• superior for eye movements
• inferior for hearing

Question 4

What is the anatomy of the dorsal aspect of the pons?

Answer 4

It is linked with the cerebellum and limited by the 4th ventricle
- along the floor of the 4th ventricle are the facial colliculi

Question 5

What is the anatomy of the dorsal aspect of the medulla?

Answer 5

Dorsal columns and nuclei - gracile and cuneate tubercle

Question 6

What is the anatomy of the ventral aspect of the midbrain?

Answer 6

Cerebral peduncles

- large white fibre tracts from motor cortex to periphery

Question 7

What is the anatomy of the ventral aspect of the pons?

Answer 7

Attached to the cerebellum dorsolaterally by cerebellar peduncles (superior, middle and inferior)

Question 8

What is the anatomy of the ventral aspect of the medulla?

Answer 8

Rostrally two bulges can be seen - inferior olivary nuclei

- pyramids descending to the pyramidal decussation

Question 9

What is the tectum?

Answer 9

The roof of the 4th ventricle - the colliculi, located only in the midbrain

Question 10

What is the tegmentum?

Answer 10

The region of the brainstem that is continuous with the spinal cord (dorsal)
- cranial nerves and the reticular formation are found within

Question 11

What is the basis?

Answer 11

Associated with movement (ventral), descending motor control

Question 12

Which cranial nerve does not exit the ventral surface of the brainstem?

Answer 12

CNIV

Question 13

What is the location and development of sensory and motor columns in the brainstem?

Answer 13

Sensory nuclei develop from the Alar plate and are located laterally. Motor nuclei develop from the basal plate and are located close to the midline

Question 14

What are the 3 motor columns of nuclei in the brainstem?

Answer 14

1. General somatic motor
2. Branchial motor
3. Visceral motor

Question 15

What are the 3 sensory columns of nuclei in the brainstem?

Answer 15

1. General and special visceral (taste)
2. General somatic
3. Special sensory

Question 16

What is the reticular formation?

Answer 16

Part of the tegmentum that is involved with maintaining alert conscious state, and involved in motor reflexes and autonomic functions

Question 17

What is the nucleus ambiguus?

Answer 17

Mostly a motor nucleus, lies behind the inferior olive, contains CNIX and CNX nuclei

• IX does stylopharyngeus
• X does levator palati

Question 18

What is the nucleus solitarius?

Answer 18

Extends from the pons to the level of the nucleus gracilis
Rostrally: gustatory nucleus (CNVII, CNIX, CNX)
Caudally: visceral sensory division (CNX - afferents from heart and abdominal viscera) (CNIX - baroreceptors and chemoreceptors from carotid body and sinus)