Girolamo Fabrici d'Acquapendente

Hieronymus Fabricius
Girolamo Fabrizi d' Acquapendente
Born	20 May 1537 Acquapendente
Died	21 May 1619 (1619-05-22) (aged 82) Padua
Nationality	Italian
Fields	Anatomy
Doctoral advisor	Gabriele Falloppio
Doctoral students	William Harvey Adriaan van den Spieghel Johannes Heurnius Jan Jesenius Salomon Alberti

Hieronymus Fabricius or Girolamo Fabrizio, known also by his full Latin and Italian names, Fabricus ab Aquapendente or Girolamo Fabrizi d'Acquapendente, (1537–1619) was a pioneering anatomist and surgeon known in medical science as "The Father of Embryology."

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.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 was the first to describe the membranous folds that he called "valves" in the interior of veins. 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.