Amatus Lusitanus

João Rodrigues de Castelo Branco, better known as Amato Lusitano and Amatus Lusitanus (1511–1568), was a notable Portuguese Jewish physician of the 16th century. Like Herophilus, Galen, Ibn al-Nafis, Michael Servetus, Realdo Colombo and William Harvey, he is credited as making a discovery in the circulation of the blood. He is said to have discovered the function of the valves in the circulation of the blood. Provided by Wikipedia