ABSTRACT

The basic function of the cardiovascular system is transport. This is the system that is responsible for carrying gases, nutrients, waste products, cells, hormones, and other substances from one part of the body to another. As such, it plays a major part in homeostasis through its role in regulating the composition of both intracellular and extracellular fluids. The system is also critical in temperature regulation. Finally, it is the circulatory system that carries defensive elements (cells and molecules of the immune system) to areas of the body that require them. Physically, the system consists of a pump (the heart), a network of tubes (the vascular system), and a transport fluid (the blood). All three components can be affected by toxicants, and we will consider each of them in turn.