Heart

The heart is a muscular organ located in the chest cavity. Rucut shape and size of a fist. It weighs approximately 300 grams. Cardiac function as a blood pumping. The movement of the heart as hands clenching and unclenching. His movements are constantly and never stops. The heart continues to beat for human and animal life. Blood pumped by the heart circulated throughout the body through the arteries. The blood that is in the whole body flowed again into the heart through the veins is called venous.
Heart consists of the heart wall and heart room. Heart wall covering membranes covering the heart, cardiac muscle, and the membrane lining the heart room. The heart consists of four chambers, the right atrium, left atrium, right ventricle, and the left ventricle. Among the booths and foyer are heart valves. Heart valves to prevent blood mixing clean and dirty blood.
Cardiac septum divides the heart cavity into two parts. Blood on the left side of the heart contains a lot of oxygen (O2) and the right side contains carbon dioxide (CO2). Total heartbeat we are not always the same. At rest, our heart rate less than at work or after work. At work our bodies need more oxygen. The heart beats faster as the blood circulated more rapidly throughout the body. Heart rate can be known by pressing the wrist.