The Brainstem

Question 1

Answer 1

Question 2

What is the brainstem?

Answer 2

Part of the brain that lies superior to the spinal cord

3 parts

Midbrain

Pons

Medulla

Question 3

What cranial fossa does the brainstem lie in?

Answer 3

Foramen magnum

Question 4

Embryologically which 2 vesicles of the neural tube give rise to the brainstem?

Answer 4

Mesencephalon

Rhombencephalon

Question 5

What are the cavities of the brainstem?

Answer 5

Cerebral aqudeuct

4th ventricle

Question 6

What is the groove that seperates the pons from medulla?

Answer 6

Pontomedullary junction

Question 7

Which cranial nerves emerge from the pontomedullar junction?

Answer 7

Glossopharyngeal- Emerges from the lateral side mid pons

Vagus- Lateral side

Hypoglossal- Pyramids laterally

Accessory- Lateral side (most inferior)

Question 8

What do the olives do?

Answer 8

Inferior Olivary nucleus which is implicated in motor coordination

Question 9

What do the pyramids do?

Answer 9

Motor fibres – Corticobulbular & Corticospinal tratcs

Question 10

What are the decussation of the pyramids?

Answer 10

Allow fibres to cross over

Question 11

Posteriorly on the medulla, identify the parts of the medulla known as the “open” and “closed” part. Which of these is superior and which inferior?

Answer 11

Open = Superior part, Closed = Inferior part.

Question 12

WHat structure does the open part of the medulla open into?

Answer 12

The fourth ventricle

Question 13

What does the medulla pass through to become the spinal cord?

Answer 13

Foramen magnum

Question 14

Answer 14

Question 15

Which part of this section would motor fibres (of the pyramidal tract) and sensory fibres that form the medial lemniscus occupy?

Answer 15

Motor Fibres – In small separate tracts dispersed within the Pontine Nuclei at anterior.

Sensory fibres – Sits in the middle – between Pontine nuclei & nuclei of Reticular formation

Question 16

Answer 16

Question 17

Answer 17

Question 18

What lies superior and ifnerior to the midbrain?

Answer 18

Superior- Diencephalon

Inferior- Pons

Question 19

The cerebral peduncles - what kind of fibres make up the cerebral peduncles and where are they destined for?

Answer 19

Motor fibres destined for the cerebral hemispheres

Question 20

Answer 20

Question 21

What is the diencephalon made up on?

Answer 21

Thalamus, Hypothalamus (& Pituitary) and the Epithalamus (Pineal Gland).

Question 22

What does the diencephalon lie between?

Answer 22

Cerebral Hemispheres and Midbrain

Question 23

Most of these structures are deep and cannot be seen from the surface except for a small part of the hypothalamus.

What are the surface projections visible on the surface of the hypothalamus called?

Answer 23

Mamillary body