Circle of Willis

Circle of Willis is an important part of the brain's blood supply system. Named after the English physician Thomas Willis, it is a circular network of arteries that provides blood to the brain and surrounding structures.

Anatomy

The Circle of Willis is located at the base of the brain. It is formed by the joining of the left and right internal carotid arteries and the basilar artery, a major blood vessel that supplies the posterior part of the brain. The Circle of Willis also includes the anterior cerebral artery, middle cerebral artery, and posterior cerebral artery, which supply blood to the front, middle, and back of the brain, respectively.

Function

The primary function of the Circle of Willis is to provide a redundant supply of blood to the brain. This redundancy is important because it ensures that the brain will continue to receive blood, and therefore oxygen and nutrients, even if one of the arteries becomes blocked or narrowed. This is known as collateral circulation.

Clinical significance

The Circle of Willis is a critical structure in the brain, and abnormalities or diseases affecting it can have serious consequences. For example, aneurysms (bulges in the walls of the arteries) can form in the Circle of Willis, which can lead to stroke if they rupture. Additionally, variations in the structure of the Circle of Willis can affect the distribution of blood in the brain, which can contribute to the development of certain neurological conditions.

See also

• Cerebrovascular disease
• Stroke
• Aneurysm