Antonio Pacchioni (13 June 1665– 5 November 1726) was an Italian scientist and anatomist, who focused chiefly on the outermost meningeal layer of the brain, the dura mater. Pacchioni's granulations (or Pacchionian bodies), where the arachnoid layer protrudes through the dura, are named after him (although they are now generally known as arachnoid granulations). Biography Pacchioni was born in Reggio Emilia, where he later attended university. He received his degree in medicine in 1688, and left for Rome in 1689. Pacchioni studied medicine at the University of his native city, obtaining his degree on April 25, 1688. The next year he moved to Rome to devote himself to anatomy in particular; he spent his most productive years in Rome. He was a friend and student of Marcello Malpighi (1628-1694), who lived in Rome from 1691 to 1694. First attending the Santo Spirito in Sassia Hospital, he was an assistant physician at the Ospedale della Conzolazione from May 26, 1690 to June 3, 1693, and then remained for six years in Tivoli as the town doctor. In 1699 Pacchioni returned to Rome and established a successful medical practice. He later became head physician at the Hospital of San Giovanni in Laterano and then at the Ospedale della Consolazione. In Rome, he made the acquaintance of the clinician and botanist Giovanni Maria Lancisi (1654-1720), with whom he collaborated in the publication of the anatomical plates of Eustachius in 1714. Pacchioni's most important works particularly concerned the anatomy and function of the dura mater. His first dissertation on this dates from 1701 on, the most important being Dissertatio epistolaris de glandulis ... (1705) in which he described the arachnoidal granulations that are named after him. Career and Life Pacchioni was a "short man, with oblong face, vivid eye and a rather melancholic temperament" Following the customs of his time, he initially studied philosophy and only later turned to medicine, demonstrating a natural talent for anatomical dissection. He worked under the guidance of Antonio Vallisneri (1661-1730), Professor of Medicine at the University of Padova and member of the Royal Society of London (Vallisneri is also credited with the first description of the anatomical features of Stein Leventhal syndrome). After moving to Rome, he first attended the Ospedaledi S. Spirito in Sassia and then successfully applied for a position as assistant physician at the Ospedale della Consolazione (May 26, 1690), well known at that time