You use your heart every day and every night.It goes beat, beat, beat pumping the blood around your body. Oxygen and carbon dioxide that is being carried by blood first enters the heart through the right and left upper chambers. The tiny cavities get filled with blood and grow. When they contract the blood pushes the flaps of the tricuspid and Mitral Valves open so that the blood can move on to the lower chambers. When the blood is finished in the lower valves the flaps close up so the blood will not flow the wrong way. The two valves that control the blood leaving the lower chambers are called Semilunar Valves.They act in a similar way opening to allow blood to pass into the aorta and the pulmonary artery on the right. Then they close to stop the blood from flowing backwards.
Did you know...
Your heart never rests and its about the size of your fist!
Your heart pumps more than 200 million litres of blood in a lifetime!
Merry Christmas from Miss S. & Miss T.
7 years ago