Ibn Al Nafis, born 1213, was the first to discover the "circulation lesser" and describe the blood flow from the right ventricle to the lungs then back to the left ventricle 300 years before William Harvey. He bravely rejected the theory of Galen (130-200 AD) and Avicenna (980-1037 AD) which stated that the blood from the right ventricle passes through "invisible" holes in the ventricular septum to the left ventricle. Also was the first to note that the nourishment of the heart muscle is coming from the coronary arteries rather than from the inside of the ventricular cavity as described by earlier scholars.