2THE CARDIOVASCULAR SYSTEM: THE HEART Cardiology– Is a medical specialty concerned with the diagnosis and treatment of heart disease. Cardiovascular System(the heart, blood vessels, and blood). The heartis the center of the cardiovascular system. (The heart propels blood through an estimated 100,000km (60,000mi) of blood vessels). (At rest, pumps 30 times its own weight per minute - about 5 liter (5.3 qt) to the lungs and the same volume to the rest of the body). (At rest, the heart would pump more than 14,000 liters (3,600 gal) of blood in a day or 10 million liters (2.6 million gal) in a year). OVERVIEW OF THE CIRCULATIONThe heart, with each beat, pumps blood into two close circuits: (1) Systemic circulation(2) Pulmonary circulation1. Systemic Circulation- The left side of the heart is the pump for the systemic circulation. Receives freshly oxygenated blood from the lungs and propel it into the largestartery in the body, the aorta- then to smaller systemic arteries- then to arterioles- and then to capillary. Through thin capillary walls, exchange of nutrients and gases occur. Blood unloads oxygen (O2) and picks up carbon dioxide (CO2). Capillary conects to venule.