ABSTRACT
The circulatory system is made up of the cardiovascular or blood vascular and lymphatic systems and performs the major roles of transporting nutrients and oxygen to every cell of the body and removal of metabolic waste products including carbon dioxide from the body. The system also plays a major role in the maintenance of body homeostasis. The circulatory system has been designed according to the metabolic activity and size of vertebrates. As working tissues such as muscle consume large quantities of nutrients and oxygen thus generating corresponding quantities of toxic wastes and heat, the circulatory system has to function in a coordinated manner to meet the metabolic requirements of all tissues in the body. The cardiovascular system consists of a closed circuit system that comprises a muscular pump, blood vessels that include arteries, veins and capillaries and blood. The blood is important in the biochemical and physiological functions of the system. The cardiovascular system has also evolved elaborate feedback controls. The lymphatic system drains lymph that is derived from blood and tissue fluid back to the cardiovascular system through the lymphatic vessels.
