Brain Vasculature

Question 1

What arteries supply the brain?

Answer 1

Internal carotid arteries & Vertebral arteries

Question 2

Where does the internal carotid artery originate?

Answer 2

• Terminal branch of common carotid arteries

- Enter base of skull through carotid canal

Question 3

Where do the vertebral arteries originate?

Answer 3

• Branches of the subclavian
• Ascend transverse foramina of cervical vertebrae 1-6
• Enter skull through foramen magnum

Question 4

What is the path of venous drainage in the brain? (superficial)

Answer 4

• Valveless veins
• Cerebral veins, diploid veins and emissary veins all pool into the venous sinuses which then flow into the internal jugular vein

Question 5

What is the path of venous drainage in the deep parts of the brain?

Answer 5

Venous Tributaries –> Thalamostriate Veins (vena terminalis) + Choroidal veins –> Internal Cerebral Veins —> Great Cerebral Vein (of Galen) –> Straight Sinus [other tributaries and basal veins join in throughout]

Question 6

What two main things cause strokes or cerebrovascular accidents?

Answer 6

Occlusion or Hemorrhage

Question 7

What is Occlusion?

Answer 7

It is blockage of a vessel by thrombus or embolus –> Ischemia –> Infarction &/or Necrosis

• Intracranial occlusion (embolic or thrombotic)
• Extracranial occlusion (usually thrombotic)

Question 8

What is hemorrhage?

Answer 8

It is from a vessel (often associated with hypertension)

• Intracerebral (perforating vessels)
• Aneurysm

Question 9

Ischemia

Answer 9

Local anemia due to lack of blood flow

Question 10

Infarction

Answer 10

Severe ischemia leading to cell death or necrosis

Question 11

Thrombosis

Answer 11

Clot that forms in place where it blocks blood flow

Question 12

Embolus

Answer 12

Clot that forms in one location and travels to the brain where it blocks blood flow