A one-paragraph description of the human heart as a hollow muscle in the middle of the chest that pumps blood around the body, supplying cells with oxygen and nutrients. It explains how the septum divides the heart into left and right sides, each with an upper atrium and a lower ventricle, and traces the two circuits of blood flow: oxygenated blood from the pulmonary veins through the left atrium and ventricle and out via the aorta, and deoxygenated blood from the vena cava through the right side to the lungs via the pulmonary artery.
It ends by noting that the resting heart beats 60 to 80 times a minute and may reach 200 beats a minute during exercise, stress or excitement.
