Arteries – are the blood vessels that deliver oxygen-rich blood from the heart to the tissues of the body. Each artery is a muscular tube lined by smooth tissue and has three layers: intima, media, and adventitia.

Vena Cava – A large vein that carries blood to the heart from other areas of the body. The vena cava is the largest vein in the body.

Vein – A blood vessel that carries blood that is low in oxygen content from the body back to the heart. Veins are part of the afferent wing of the circulatory system, which returns blood to the heart.