All living cells require oxygen and nutrients to survive. These cells also produce waste, such as carbon dioxide, that must be removed from the body. Cells must also fight of infectious diseases to survive. All of these functions are the job of the cardiovascular system. To accomplish these tasks, the cardiovascular system relies on several functions including the circulatory system, the lymphatic system and the hepatic system.
The circulatory system is responsible for transporting blood throughout the body. The circulatory system includes the heart, arteries, arterioles, capillaries, venules and veins. The heart is the central pump for the system. The circulatory system can be considered as two separate system connected by the heart. These are the pulmonary circulation system and the systemic circulation system. The pulmonary circulation, systemic circulation and coronary circulation. Pulmonary circulation pumps blood through the lungs to pick up oxygen. Systemic circulation delivers oxygen-rich blood to the body organs, tissues and cells. Some people also define a coronary circulation system that provides blood to nourish the heart cells. This would be part of the systemic circulation. For more details, see our circulatory system section.
The lymphatic system consists organs, ducts and nodes responsible for transporting lymph throughout the body. The lymphatic system helps the body, and cells in particular, fight off infectious diseases. For more details, see our lymphatic system section.
The hepatic system, or hepatic portal system, is responsible for storing nutrients, and cleansing or detoxifying the blood. It includes the veins carrying blood from the gastrointestinal (GI) tract including the stomach, spleen, intestines, pancreas and gallbladder. The blood from the GI tract enters the liver where nutrients are processed and stored, and where the blood is detoxified before returning into the blood stream. For more details, see our hepatic system section.