The circulatory system of a rat is responsible for circulating blood through the body and organs. Pulmonary circulation refers to the process of oxygenating the body, while systemic circulation refers to the moving of blood through the body for nourishment. The function and general structure of the circulatory system of a rat are almost identical to the human circulatory system.
The circulatory system has three major roles in the body: excretion, respiration, and nutrition. Excretion refers to the transport of waste products to the kidneys, respiration refers to the carrying of carbon dioxide from the tissues to the respiratory organs which takes place after the carrying of oxygen from the respiratory surfaces to the tissues, and nutrition refers to the transport of nutrients from the alimentary canal to the tissues.
The heart of a rat consists of two separate pumps which are located together in the same organ. The left side takes oxygenated blood from the lungs and delivers it to the body. The right half of the heart takes the deoxygenated blood from the body and pumps it out to the lungs. The circulatory system is essentially responsible for unifying the body and creating a web of interaction from organ to organ within the rat.