Lecture 11: Brainstem Networks

Question 1

What arises from the mesencephalon?

Answer 1

The midbrain.

Question 2

What arises from the metencephalon?

Answer 2

The pons and the cerebellum.

Question 3

What arises from the myelencephalon?

Answer 3

The medulla oblongata.

Question 4

Which division of the brainstem is involved in vision, hearing and motor control?

Answer 4

The midbrain.

Question 5

Which division of the brainstem is the pneumotaxic centre (involved in rhythmic respiratory control)?

Answer 5

The pons.

Question 6

Which division of the brainstem is involved in cardiac function, respiratory function, vasomotor function and vomiting?

Answer 6

The medulla oblongata.

Question 7

Which aqueduct runs through the midbrain?

Answer 7

The cerebral aqueduct.

Question 8

Where is the red nucleus located?

Answer 8

In the midbrain.

Question 9

Why is the red nucleus red?

Answer 9

It contains numerous blood vessels.

Question 10

Where does the red nucleus receive inputs from?

Answer 10

The cerebrum and the cerebellum.

Question 11

What does the red nucleus do?

Answer 11

It issues subconscious motor commands that are involved in muscle tone and posture.

Question 12

Which contains melanin, the Substantia nigra or the red nucleus?

Answer 12

The Substantia nigra.

Question 13

The midbrain has two systems of dopaminergic neurons, what are they?

Answer 13

The nigrostriatal system (from Substantia nigra to striatum - motor coordination)
&
The mesolimbic system (involved in behavioural reward)

Question 14

The pons contains sensory and motor nuclei for which 4 cranial nerves?

Answer 14

Trigeminal (V)
Abducens (VI)
Facial (VII)
Auditory/Vestibular (VIII)

Question 15

What are the two ridges of the medulla oblongata called?

Answer 15

The medullary pyramids.

Question 16

The medullary pyramids are formed of what?

Answer 16

Large motor corticospinal tracts.

Question 17

Where do the fibres of the large motor corticospinal tracts decussate (cross-over)?

Answer 17

Just above the junction between the spinal cord and the medulla.

Question 18

Name the two main autonomic nuclei in the medulla oblongata and an additional one.

Answer 18

Cardiovascular centres
Respiratory rhythmicity centres.
Extra options: emesis (vomiting), deglutition (swallowing), coughing, hiccuping and sneezing.

Question 19

The medulla oblongata contains the sensory and motor nuclei of which 5 cranial nerves?

Answer 19

Auditory/Vestibular (VIII)
Glossopharyngeal (IX)
Vagus (X)
Accessory (XI)
Hypoglossal (XII)

Question 20

Which two relay nuclei in the medulla oblongata pass somatosensory information to the thalamus?

Answer 20

The nucleus gracilis and the nucleus cuneatus.

Question 21

Which relay nuclei of the medulla oblongata relay info from the spinal cord, brainstem and cerebral cortex to the cerebellar cortex?

Answer 21

The olivary nuclei.

Question 22

Which two tracts are involved in voluntary movement?

Answer 22

Lateral corticospinal tract
&
Ventral corticospinal tract

Question 23

Which motor pathway is related to equilibrium and antigravity reflexes?

Answer 23

Vestibulospinal tract.

Question 24

Where does the vestibulospinal tract originate?

Answer 24

In the vestibular nuclei of the medulla.

Question 25

What is the function of the reticular formation and where is it located?

Answer 25

It functions as a filter for sensory input, projecting to the thalamus, and is located in the brain stem (running as a “core” throughout all sections outside of the major nuclear groups of the brainstem).