Brain Arterial Supply / Venous Drainage

Question 1

What are the two groups of arteries which supply the brain?

Answer 1

• Carotid a.
• Vertebral a.

Question 2

Draw and label the aortic arch, and where the carotid and vertebral arteries arise from.

Answer 2

Refer to Notion.

Question 3

Draw and label the branches of the external carotid artery.

Answer 3

Refer to Notion.

Question 4

What does the anterior cerebral artery mostly supply?

Answer 4

Medial surface of brain lobes

Question 5

What does the middle cerebral artery mostly supply?

Answer 5

• Lateral surface of brain lobes
• Lenticulostriate branches perforate into brain

Question 6

Draw and label the circle of Willis.

Answer 6

Refer to Notion.

Question 7

What is the importance of the circle of Willis?

Answer 7

Collateral circulation can compensate for stenosis in a part of the circle, thus preserving cerebral perfusion

Question 8

What happens in subclavian steal syndrome?

Answer 8

If proximal part of subclavian artery is stenosed, blood is stolen from vertebral artery to preserve upper limb blood flow

Question 9

What do the vertebral arteries supply?

Answer 9

1. Spinal a.
2. Cerebellar a.
3. Labyrinthine a. (inner ear)
4. Basilar a. (anastomoses with PCA to supply inferior surfaces of brain lobes)

Question 10

How does the venous drainage of the body work?

Answer 10

Superficial + Deep cerebral v. > dural venous sinuses (between dura mater infoldings) > IJV