The human heart consists of four chambers, two atria and two ventricles. Each is made up of several layers of cardiac muscles arranged in circles and spirals. During the contraction phase, called the systole, oxygenated blood is pumped out of the left ventricle into the aorta and from there through the arteries to all organs of the body. Carbon dioxide, a waste product of this process, is collected in the blood. The blood is passed back to the right atrium through the veins and the vena cava during the diastole (or relaxation) period of the heart. From there, it is pumped into the right ventricle and to the pulmonary artery to be sent to the lungs where carbon dioxide is removed and oxygen is added.
The human heart consists of four chambers, two atria and two ventricles. Each is made up of several layers of cardiac muscles arranged in circles and spirals. During the contraction phase, called the systole, oxygenated blood is pumped out of the left ventricle into the aorta and from there through the arteries to all organs of the body. Carbon dioxide, a waste product of this process, is collected in the blood. The blood is passed back to the right atrium through the veins and the vena cava during the diastole (or relaxation) period of the heart. From there, it is pumped into the right ventricle and to the pulmonary artery to be sent to the lungs where carbon dioxide is removed and oxygen is added.
正在翻译中..