Neuroscience anatomy - Blood supply to the brain

Which two main arteries bring blood to the brain?

1. A. carotis internal

   • Anterior circulation

   • Supplies the forebrain

2. A. vertebralis

   • Posterior circulation

   • Supplies the hindbrain

What is this structure called? What is its function?

• The Circle of Willis

  • A ring of arteries at the base of the brain

  • Connects the anterior (internal carotid arteries) and posterior (vertebral/basilar) arteries circulations

  • Provides alternative routes that blood can take through backup vessels when a primary artery is blocked or narrowed (occlusion), preventing oxygen deprivation (ischemia) and potential stroke damage to brain tissue

What are these arteries called?

1. A. carotis interna

2. A. basilaris

3. A. vertebralis

4. A. cerebri anterior

5. A. cerebri media

6. A. cerebri posterior

Which artery distributes blood to each of these brain regions?

1. A. cerebri anterior

2. A.cerebri media

3. A. cerebri posterior

What are common stroke symptoms if a clog forms in A. cerebri anterior?

1. Personality changes

2. Weakness in legs

What are common stroke symptoms if a clog forms in A. cerebri media?

1. Aphasia

   • Language disorder that affects your ability to speak and understand what others say

2. Weakness in face, arm, and hand

What is a common stroke symptom if a clog forms in A. cerebri posterior?

• Visual defects

Describe the pathways that supply the brain with blood

• Brain needs constant supply of oxygen and glucose

Anterior circulation pathway

1. Internal carotid arteries (A. carotis interna) enter skull via carotid canal

2. The internal carotid arteries split into A. cerebri anterior and A. cerebri media

3. A. cerebri anterior supplies the medial frontal/parietal lobes and corpus callosum with blood + A. cerebri media supplies lateral hemispheres and basal ganglia with blood

Posterior circulation pathway

1. Vertebral arteries (A. vertebralis) unite to a basilar artery (A. basilaris)

2. A. basilaris branches into different arteries that all terminates as posterior cerebral arteries (A. cerebri posterior)

3. The posterior cerebral arteries supplies femoral lobes, thalamus, and midbrain with blood

Circle of Willis integration

• Links anterior cerebral arteries, internal carotid arteries and posterior cerebral arteries, enabling rerouting of one vessel occludes