Beating heart Small 131×320 Medium 262×640 Large 419×1024 Download Tiff Original 983×2400 | (605.3 KB) Description "Diagram of the rush of blood when the heart beats. The valves v open above are closed below while the valves s closed above are open below." —Davison, 1910 Keywords anatomy, circulatory, heart, heartbeat, pulminary, ventricle Galleries Human Coronary and Pulmonary Circulation Source: Alvin Davison, Health Lessons (New York: American Book Company, 1910) 88