While most arteries do carry oxygenated blood, the pulmonary artery does not. The pulmonary artery is a main artery that supplies the lungs with deoxygenated blood.
Arteries and veins are the two major structures that transport blood throughout the body as part of the circulatory system. Arteries are defined as leaving the heart, while veins are defined as bringing blood back into the heart. Arteries and veins are both considered blood vessels, but there is also one more type of vessel called capillaries. Capillaries are structures that allow gases located at muscle cells and the lungs to be exchanged, specifically oxygen and carbon dioxide.