The Brainstem

Question 1

What are the three major fibre tracts of the spinal cord?

Answer 1

Ascending

1. Dorsal column - medial lemnicus system (touch)
2. Anterolateral system (pain)

Descending

3. Corticospinal tract

Question 2

Apart from the face, what else do certain cranial nerve supply?

Answer 2

CN9,10 and 11 also supply visceral, sensory and motor innervation to neck, chest and most of abdominal organs

Question 2

Which CNs exit from the medulla?

Answer 2

9-12

Question 2

Where does decussation occur in the anterolateral system (pain)?

Answer 2

In the spinal cord

Question 3

Are cranial nerve nuclei located in the tectum or tegmentum?

Answer 3

Tegmentum

Question 4

Ancephalic babies, if born, are able to do what?

Answer 4

Swallow, cry, breathe and suckle

Question 5

How is the tegmentum located in relation to the rest of the CNS?

Answer 5

It is the central pathway of the brainstem which is continuous with the spinal cord - everything coming or going to PNS goes through it

Question 5

Where does decussation occur in the corticospinal tract?

Answer 5

Pyramidal decussation

Question 6

Where does decussation occur in the dorsal column tract (touch)

Answer 6

Medial lemniscus of the medulla

Question 7

What are 3 parts of the brainstem in decending order?

Answer 7

Midbrain

Pons

Medulla oblongata

Question 7

What is the function of the caudal reticular formation?

Answer 7

Crucial functions in motor reflexes and automonic functions

eg vomiting

Question 8

What embryological feature do the sensory nuclei develop from?

Answer 8

The alar plate

Question 9

What are the general functions of the brainstem?

Answer 9

Reflexive and unconscious behaviour

Modulation of various arousal and conscious states

Question 9

Are the CN motor nuclei located closer or further from the midline cf. to the sensory nuclei?

Answer 9

Motor are closer

Sensory are more lateral

Question 11

How many colliculi are there on the midbrain?

Answer 11

4

Question 12

Where in the brainstem is the reticular formation located?

Answer 12

At all level - also extends rostrally into the thalamus and caudally into the grey matter of the spinal cord

Question 13

What is on the dorsal aspect of the medulla?

Answer 13

Dorsal columns and nuclei

Question 14

What embryological feature do the motor nuclei develop from?

Answer 14

The basal plate

Question 15

Which cranial nerves are a mixture of motor and sensory?

Answer 15

5,7,9,10

Question 16

Where are the cerebral peduncles found?

Answer 16

Ventral aspect of the midbrain

Question 17

Is the recticular formation on the dorsal or ventral aspect?

Answer 17

Dorsal

Question 18

Which cranial nerves exit from the midbrain?

Answer 18

3,4

Question 19

Where do the cranial nerve nuclei lie during development?

Answer 19

Next to the ventricles

Question 21

What is on the ventral aspect of the midbrain?

Answer 21

Cerebral peduncles - motor tract from the motor cortex

Question 22

What is the tectum?

Answer 22

The roof of the midbrain - located superiodorsal

Question 24

T/F the colliculi of the midbrain are located in the tegmentum?

Answer 24

False, they’re in the tectum

Question 25

In general, in the brainstem the ventral aspect contains … while the dorsal aspest contains …

Answer 25

Motor control tracts

Cranial nerves

Question 26

The basis of the brainstem is important for what?

Answer 26

Descending motor control

Question 28

What the features of the posterior aspect of the pons?

Answer 28

4th ventricle lies on top

Facial colliculi formed by the abducens nucleus and CN7

Question 30

Which CNs exit from the pons?

Answer 30

5-8

Question 31

Which cranial nerves exit from above the midbrain

Answer 31

1,2

Question 32

What is the function of the midbrain colliculi?

Answer 32

Eye movement control

Hearing

Question 33

Where in the cranium is the braistem located?

Answer 33

In the posterior cranial fossa

Question 34

Where is the pyramidal decussation found?

Answer 34

At the base of the medulla

Question 35

What are the bumps on the posterior aspect of the midbrain called?

Answer 35

Colliculi (meaing hills)