Heart and lungs. Computer artwork showing a section through a human heart (centre) and the bronchial trees of the lungs (red, left and right). The heart is composed of four chambers. Two upper chambers, the atria, and two lower chambers, the ventricles. The left and right side of the heart are separated by the septum (down centre). Between each atrium and ventricle and between the chambers and the major blood vessels are valves that prevent the backflow of blood.
Model release not required. Property release not required.