The heart is a fist-sized organ in the chest cavity that weighs roughly 450 grams (1 pound). The walls of the heart are made up of heart muscle, which is capable of contracting automatically at a rhythm of about 70 times per minute, thus transporting a constant flow of blood to all tissues of the body. The heart is actually made up of two blood pumps that are connected. Each pump consists of two parts: the upper one is called the atrium; the lower one is called the ventricle. Blood enters the heart from the atria and then flows into the lower ventricles. The walls of the ventricles are very thick and help pump blood out of the heart. When the heart works, the right ventricle carries blood to the lungs, where it flows through the lungs and back to the left atrium, before being carried through the left ventricle to the whole body. The role of the heart is to drive blood flow, provide adequate blood flow to organs and tissues to supply oxygen and various nutrients, and carry away the end products of metabolism (such as carbon dioxide, urea and uric acid) so that cells maintain normal metabolism and function. Various endocrine hormones and some other humoral factors in the body also have to be transported to the target cells through blood circulation to realize the humoral regulation of the body and maintain the relative constancy of the body’s internal environment. In addition, the realization of the blood defense function, as well as the regulation of the relative constant body temperature, also depends on the continuous circulation of blood in the blood vessels, and the circulation of blood is due to the role of the heart “pump” to achieve. The adult heart weighs about 300 grams, its role is huge, for example, a person in a quiet state, the heart beats about 70 times a minute, each pumping 70 milliliters of blood, then about 5 liters of blood per minute, so the projection of a person’s heart pumping blood work done in a lifetime, about the equivalent of 30,000 kilograms of objects up to the summit of the Himalayas work done.