16 - The Brainstem and Blood Supply

Question 1

What is the role of the briainstem?

Answer 1

• Its a conduit for tracts
• Its responsible for: Consciousness, the cardiovascular system, the respiratory system, and pain perception.

Question 2

What does the brainstem consist of?

Answer 2

The midbrain, pons and the medulla.

Question 3

What are the dorsal aspects of the midbrain?

Answer 3

The superior and inferior colliculus.

Question 4

What is the superior colliculus responsible for?

Answer 4

The visual reflexes as its a part of the visual pathway.

Question 5

What is the inferior colliculus responsible for?

Answer 5

The auditory reflexes as its a part of the auditory pathway.

Question 6

What are the dorsal aspects of the pons?

Answer 6

The cerebellar peduncles (Superior, middle and inferior)

Question 7

What is the role of the superior cerebellar peduncle?

Answer 7

It connects the cerebellum to the midbrain.

Question 8

What is the role of the middle cerebellar peduncle?

Answer 8

It connects the cerebellum to the pons.

Question 9

What is the role of the inferior cerebellar peduncle?

Answer 9

It connects the cerebellum to the medulla.

Question 10

What are the dorsal aspects of the medulla?

Answer 10

The Gracile tubercle and the cuneate tubercle.

Question 11

Where is the gracile tubercle located and what is it responsible for?

Answer 11

Its located towards the midline and responsible for the passage of lower limb fibres.

Question 12

Where is the cuneate tubercle located and what is it responsible for?

Answer 12

Located lateral to the gracile and responsible for the passage of the upper limb fibres.

Question 13

What is in the ventral aspects of the midbrain?

Answer 13

The crus cerebri (The cerebral peduncle)

Question 14

What does he crus cerebri do?

Answer 14

It connects the brainstem to the cerebrum.

Question 15

What is in the ventral aspect of the pons?

Answer 15

• The basilar sulcus - a groove on the ventral aspect of the pons where the basilar artery will lie?
• The bulbo pontine sulcus - Which is located between the pons and the medulla.

Question 16

What is in the ventral aspects of the medulla?

Answer 16

• The anterior median sulcus - The groove between the 2 pyramids of the medulla
• The Olives - lateral to the pyramids.

Question 17

What are some functional areas of the midbrain?

Answer 17

• Red Nucleus
• Substantia Nigra
• Corticobulbar and corticospinal fibres
• Cerebral aqueduct
• Dorsal Tectum

Question 18

What is the cause of Parkinson’s disease?

Answer 18

It a neurodegenerative disease caused by depletion in dopamine, there is usually damage to the substantia nigra.

Question 19

What are the characteristics of Parkinson’s disease?

Answer 19

A resting tremor, difficulty initiating voluntary movement and jerking.

Question 20

What are some functional areas of the midbrain?

Answer 20

• The pontine nuclei - Responsible for coordinating nuclei.
• The tegmentum.
• The sensory tracts.

Question 21

What are the 4 sensory tracts that pass through the pons?

Answer 21

• Descending corticospinal tracts
• Descending corticobulbar tracts
• Ascending medial lemniscus tracts
• Ascending Spinothalamic

Question 22

What are some functional parts of the medulla?

Answer 22

• Inferior olivary nucleus
• Pyramids

Question 23

Where does the corticospinal tract come from and what is it responsible for?

Answer 23

• Travels from the cerebrum to the skeletal muscles, from the primary motor cortex/pre-central gyrus.
• Allows for voluntary movement below the head and the neck.

Question 24

Where does the corticobulbar tract come from and what is it responsible for?

Answer 24

• Travels from the pre-central gyrus and runs through the internal capsule.
• Its responsible for the voluntary movement of the skeletal muscles.

Question 25

Where does the dorsal column medial lemniscus come from and what is it responsible for?

Answer 25

- Starts from the dorsal root ganglion and is processed through the Fascilicus Gracilis - Its responsible for bringing sensory info from the peripheral nerves to the cerebral cortex. Proprioception fine touch and vibration.

Question 26

Where does the spinothalamic tract come from and what is it responsible for?

Answer 26

- It starts from the dorsal root ganglion, synapsing with a second order neurone in the dorsal horn. - Its responsible for taking sensory info from the peripheral nerves to the cerebral cortex. (Pain crude touch and temperature)

Question 27

Where does the main blood supply of the brain come from?

Answer 27

The cerebral arterial circle or the circle of Willis.

Question 28

What are the 2 systems in the cerebral arterial circle?

Answer 28

The internal carotid system and the vertebral basilar system.

Question 29

Where do the 2 internal carotid arteries enter the skull from?

Answer 29

The carotid canal

Question 30

What artery does the internal carotid arise from?

Answer 30

The common carotid

Question 31

Where do the vertebral arteries enter the skull?

Answer 31

The Foramen magnum

Question 32

What artery does the vertebral artery arise from?

Answer 32

The subclavian artery

Question 33

What do the vertebral arteries fuse to form?

Answer 33

The basilar artery

Question 34

Where does the basilar artery lie?

Answer 34

In the centre of the pons.