(428) 2-Minute Neuroscience: Blood Supply of the Brain

Blood Supply of the Brain

• Overview

  • The brain receives blood primarily from two sets of arteries:

    • Internal carotid arteries: Supply ~80% of blood.

    • Vertebral arteries: Supply ~20% of blood.

Internal Carotid Arteries

• After ascending into the brain:

  • Split into:

    • Anterior cerebral arteries:

      • Supply medial parts of the frontal and parietal lobes.

      • Connected by the anterior communicating artery.

    • Middle cerebral arteries:

      • Supply the majority of the lateral surface of the cerebral hemispheres.

• Before splitting, give rise to:

  • Anterior choroidal arteries:

    • Supply various structures in the brain.

  • Posterior communicating arteries:

    • Connect internal carotid arteries to posterior cerebral arteries.

Vertebral Arteries

• Supplies:

  • Posterior inferior cerebellar arteries:

    • Supply the inferior surface of the cerebellum.

    • Often give rise to posterior spinal arteries:

      • Supply the posterior spinal cord.

  • Anterior spinal artery:

    • Supplies the anterior spinal cord.

• Join to form the basilar artery:

  • Gives rise to:

    • Anterior inferior cerebellar arteries:

      • Supply part of the cerebellar surface.

    • Superior cerebellar arteries:

      • Supply the rest of the cerebellar surface.

  • At midbrain level, splits into two posterior cerebral arteries.

Posterior Cerebral Arteries

• Supply:

  • Medial and inferior surfaces of the occipital and temporal lobes.

Circle of Willis

• The anterior cerebral, internal carotid, and posterior cerebral arteries of both sides are interconnected.

• This arrangement:

  • Allows for continuous blood flow even if a major vessel is obstructed on one side of the brain.