The heartbeatĮach atrium is connected to its ventricle by a one-way valve. Once it has received oxygen, the blood returns directly to the left side of your heart, which then pumps it out again to all parts of your body through an artery called the aorta.īlood pressure refers to the amount of force the pumping blood exerts on arterial walls. Your heart pumps the blood from the right side of your heart to your lungs so it can receive more oxygen. The blood entering the right side of your heart is low in oxygen. The right side of your heart collects blood on its return from the rest of our body. There are four chambers: the left atrium and right atrium (upper chambers), and the left ventricle and right ventricle (lower chambers).

Each side has a small collecting chamber called an ‘atrium’, which leads into a large pumping chamber called a ‘ventricle’. Your heart has a right and left side separated by a wall called the septum.

However, when necessary, such as during exercise, your heart can pump up to four times that amount per minute. If you are of average body weight and size, your body contains about five litres of blood, all of which passes through your heart every minute or so. It lies in the middle of your chest, behind and slightly to the left of your breastbone. Your heart is about the size of a clenched fist, and weighs between 300 and 450 g. The blood pumped by your heart provides your body with the oxygen and nutrients it needs to function. It is a muscle that pumps blood to all parts of your body.

Blood on the wall