Heart Structure and Blood Circulation

Ever wondered how your heart manages to pump blood to every single cell in your body? The circulatory system has two main types: closed circulation (like ours) and open circulation (like insects have).

Your heart runs two separate circuits simultaneously. Pulmonary circulation moves blood between your heart and lungs, whilst systemic circulation carries blood from your heart to the rest of your body and back again. Think of it like two different delivery routes that never mix.

The heart has four chambers that work as a team. The right atrium receives deoxygenated blood from the body through the vena cava - it has thin walls because it just needs to collect blood, not pump it hard. Blood then flows through the tricuspid valve into the right ventricle, which has thicker walls than the atrium because it needs to pump blood to your lungs through the pulmonary artery.

On the left side, the left atrium receives oxygenated blood from the lungs via pulmonary veins. The bicuspid valve controls flow into the left ventricle - the strongest chamber of all. The left ventricle has the thickest walls because it pumps oxygenated blood to your entire body through the aorta. The septum acts like a wall, preventing oxygenated and deoxygenated blood from mixing.

Quick Tip: Remember that the left ventricle is the strongest chamber because it has to pump blood much further than the right ventricle!