Aneurysm

An aneurysm (or aneurism) (from Greek ανευρυσμα, a dilatation) is a localized dilation or ballooning of a blood vessel. Aneurysms most commonly occur in the arteries at the base of the brain (the circle of Willis) and in the aorta (the main artery coming out of the heart) - this is an aortic aneurysm.

Related Topics:
Greek - Blood vessel - Arteries - Brain - Circle of Willis - Aorta - Heart - Aortic aneurysm

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The layer of the artery that is in direct contact with the flow of blood is the tunica intima, commonly called the intima. This layer is made up of mainly endothelial cells. Adjacent to this layer is the tunica media, known as the media. This "middle layer" is made up of smooth muscle cells and elastic tissue. The outermost layer (farthest from the flow of blood) is known as the tunica adventitia or the adventitia. This layer is composed of connective tissue.

Related Topics:
Tunica intima - Endothelial cell - Tunica media - Smooth muscle - Tunica adventitia - Connective tissue

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