Hieronymus Fabricius

Girolamo Fabrici d'Acquapendente, also known as Girolamo Fabrizio or Hieronymus Fabricius (20 May 1533 – 21 May 1619), was a pioneering anatomist and surgeon known in medical science as "The Father of Embryology." Life and accomplishments Born in Acquapendente, Latium, Fabricius studied at the University of Padua, receiving a Doctor of Medicine degree in 1559 under the guidance of Gabriele Falloppio. He was a private teacher of anatomy in Padua, 1562–1565, and in 1565, became professor of surgery and anatomy at the university, succeeding Falloppio. In 1594 he revolutionized the teaching of anatomy when he designed the first permanent theater for public anatomical dissections. Julius Casserius (1552–1616) of Piacenza was among Fabricius' students, Anselmus Boetius de Boodt (1550-1632) also received his lessons there in 1586. William Harvey (1578–1657) and Adriaan van den Spiegel (1578–1625) also studied under Fabricius, beginning around 1598. Julius Casserius would later succeed Fabricius as Professor of Anatomy at the University of Padua in 1604, and Adriaan van den Spiegel succeeded Casserius in that position in 1615. By dissecting animals, Fabricius investigated the formation of the fetus, the structure of the esophagus, stomach and intestines, and the peculiarities of the eye, the ear, and the larynx. He rediscovered the membranous folds that he called "valves" in the interior of veins, though they were first described by Charles Estienne in 1545. Fabricius rediscovered them in 1574, and was the first to fully describe them including their function in 1603. These valves are now understood to prevent retrograde flow of blood within the veins, thus facilitating antegrade flow of blood towards the heart, though Fabricius did not understand their role at that time. His pupil William Harvey deduced the circulation of blood.