Which artery is part of the Circle of Willis?

The anterior communicating artery is a crucial component of the Circle of Willis, which is a cerebral arterial circle located at the base of the brain. This artery connects the left and right anterior cerebral arteries, providing an important collateral circulation pathway.

In the event of a blockage or narrowing in one of the internal carotid arteries or in one of the anterior cerebral arteries, the anterior communicating artery plays a vital role in maintaining blood supply to the brain. This anatomical feature helps to ensure that essential blood flow continues to the regions of the brain that these arteries supply, enhancing the resilience of the brain's vascular system.

In contrast, while the middle cerebral artery, posterior communicating artery, and subclavian artery each play important roles in cerebral or systemic circulation, they do not contribute to the Circle of Willis structure in the same way as the anterior communicating artery. The middle cerebral artery supplies a large portion of the lateral aspect of the cerebral hemispheres, and the posterior communicating artery connects the internal carotid artery to the posterior cerebral artery, while the subclavian artery is primarily involved in supplying blood to the arms and not directly involved in the configuration of blood flow at the base of the brain.