The circulatory system in human body is a network of blood, blood vessels (arteries and veins), and the heart. This network supplies tissues in the body with oxygen and other nutrients that are needed by the body. The circulatory system is also called the cardiovascular system or the vascular system. Arterial disease includes any condition that affects your arteries of the circulatory system.
Human heart is a wonderful organ. It beats about 60 to 100 times each minute. That's about 100,000 times each day. It is part of the ciculatory system. Any problem with the functioning of the heart can also affect pumping of the blood to distant organs and can cause diseases associated with your ciculatory system including the peripheral vascular diseases.
Peripheral artery disease (also called peripheral arterial disease) is a circulatory problem in which arteries become narrowed and blood flow is reduced to the limbs such as to legs. In particular, the extremities in the body don't receive enough blood flow to keep up with demand.