Heart. Conceptual computer artwork of a human heart on a circuit board, representing the position of the heart at the centre of the body's circulatory system. The heart is a hollow muscle that pumps blood around the body. The vena cava vein (upper left) carries deoxygenated blood into the heart from the body. This blood then travels from the heart to the lungs, where it obtains oxygen, and back to the heart through the pulmonary blood vessels (centre right). The arched aorta (upper centre) is the large artery through which oxygenated blood travels to the body from the heart.