SAINS SUKAN

Heart Anatomy
The heart weighs about 350 to 450 grams in an average adult.It pumps about 80 cc of blood per heart beat. At average heart beat of 70 per minute, in a day, the heart would have pumped 8 thousand liters of blood around the body.It is on automatic. Via specialised group of cells, the heart has a natural pacemaker that will regulate the heart rate. Some specialised muscle cells act as a conducting pathway, much like electrical circuit. Signals from the pacemaker is transmitted to heart muscle in orderly fashioned. Cardiac valves separate the various chambers and great blood vessels. Acting like a door, it allows blood flow only in one direction. There are four valves in a normal heart.