Aroutine scan of an elderly man reveals partial occlusion of the right internal carotid artery, yet blood supply to his cerebrum is unimpaired. what are two possible causes of the occlusion? *

Atherosclerosis would be the occlusion.

What anastamosis is maintaining blood supply to the brain and by what routes?

●Collateral Circulation

●Collateral Willis

Explanation:

Atherosclerosisis affects arterial blood vessels by causing a thickening of the arteries by multiple plaques within the arteries.

Collateral Circulation best shows why there was adequate and necessary blood flow to the brain.

In Collateral Circulation closed smaller arteries links and connect to two bigger arteries or certain points of the same artery acting as another way of blood supply.

Collateral vessels are often closed but in people with coronary heart disease or stroke, it will expand and increase.

Note: there is something called collateral Willis referring to the choice of it remain close in some people and being open in some people.