Brain’s blood supply routes

Figure 1 depicts the brain’s blood supply routes. The Carotid arteries – both internal and external branches – serve as the main supply routes. Both originate from the common carotid artery; here we see the right-side supply routes. We have a similar system on the left side too.

Figure 1: Brain’s blood supply routes

Source:, RICE University
under the CC BY 4.0 license

This diagram shows the blood vessels in the head and brain.

The outer external branch transports oxygen and food to the face and all over the skull; the inner branch transports to the inside of the brain.

The junction where the common carotid artery divides into two is a crucial place. It is commonplace where fat deposits, a plaque develops and then narrowing the route happens. We can hear a sound – “bruit” – using a stethoscope. They are at high risk of getting a stroke either by cutting off the blood supply or by dislodging plaque particles. The plaque particles can travel higher through blood further inside and may cut off blood supply to a smaller area of the brain. This type of stroke, which is the commonest type, is called an ischemic stroke.

Figure 2 (below) illustrates the blood supply on the skull base.

Figure 2: Blood supply routes on the base of the brain:

Source:, RICE University
under the CC BY 4.0 license

This diagram shows the arteries of the brain.

Figure 3 shows the brain regions’ main supply routes: Anterior, middle, and cerebral. Knowing these supply areas is very useful because the impairments due to an interruption to the blood supply in a stroke depend on which supply route is blocked.

Figure 3: Brain’s main blood supply areas according to its supply routes

Source: Frank Gaillard. Patrick J. Lynch, medical illustrator (Brain_stem_normal_human.svg) CC BY-SA 3.0

File:Cerebral vascular territories.jpg

Author: Ed Jerard

Research analyst and health promoter in Canada

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