Heart Motu Cordis" (1628) by the English physician William Harvey. Harvey's book completely describes the systemic circulation and the mechanical force of the heart, leading to an overhaul of the Galenic doctrines. Otto Frank (1865–1944) was a German physiologist; among his many published works are detailed studies of this important heart relationship. Ernest Starling (1866–1927) was an important English physiologist who also studied the heart. Although they worked largely independently, their combined efforts and similar conclusions have been recognized in the name "Frank–Starling mechanism". Although Purkinje fibers and the bundle of His were discovered as early as the 19th century, their
Medicine in the medieval Islamic world blood is pumped to the rest of the body. According to Galen in the 2nd century, blood reached the left ventricle through invisible passages in the septum. By some means, Ibn al-Nafis, a 13th-century Syrian physician, found the previous statement on blood flow from the right ventricle to the left to be false. Ibn al-Nafis discovered that the ventricular septum was impenetrable, lacking any type of invisible passages, showing Galen's assumptions to be false. Ibn al-Nafis discovered that the blood in the right ventricle of the heart is instead carried to the left by way of the lungs. This discovery