Your heart weighs well under a pound and is only a little larger than your fist. But it is a powerful. Its job is to pump blood to the lungs and to all your body tissues. The heart is a hollow organ.
Valves regulate the flow of blood through the heart and to the pulmonary artery and the aorta.
The heart is really a double pump. It pumps this dark, bluish-red blood to the lungs. The oxygen turns it a bright red again. Smaller arteries distribute it to all parts of your body. August 1st Hepatitis B is not common in childhood it is primarily an adult disease, and is not highly contagious.