ANATOMY

Detailed explanation-1: -The heart is a hollow muscular organ about the size of a closed fist. It’s in the centre of your chest, behind the breastbone. Each heartbeat sends blood that’s rich in oxygen and nutrients to all parts of your body.

Detailed explanation-2: -The right ventricle pumps the oxygen-poor blood to the lungs through the pulmonary valve. The left atrium receives oxygen-rich blood from the lungs and pumps it to the left ventricle through the mitral valve. The left ventricle pumps the oxygen-rich blood through the aortic valve out to the rest of the body.

Detailed explanation-3: -Your heart pumps blood around the body all the time-about five litres (eight pints) of it-and this is called circulation. Your heart, blood and blood vessels together make up your cardiovascular system (or heart and circulatory system).