Herophilos

Herophilos was an ancient Greek physician and perhaps the first true anatomist in world history. Some of his key findings include identification of the ovum, Skene's gland, components of the eye (cornea, iris), the prostate gland and duodenum. As a member of the well-known scholastic community in the newly founded city of Alexandria during the single, brief period in Greek medical history when the ban on human dissection was temporarily lifted, Herophilus studied the ventricles (cavities) of the brain, the organ he regarded as the centre of the nervous system, traced the sinuses of the dura mater (the tough membrane covering the brain) to their junction, known as the torcular Herophili; and classified the nerve trunks —distinguishing them from tendons and blood vessels — as motor or sensory.

He rendered careful accounts of the eye, liver, salivary glands, pancreas, and genital organs of both sexes. A student of Hippocrates’s doctrine of medicine, which was based on balancing the four humours (body fluids) — blood, phlegm, yellow bile (choler), and black bile (melancholy) — Herophilus emphasized the curative powers of drugs, dietetics, and gymnastics. He was first to measure the pulse, for which he used a water clock. He made major discoveries regarding the cardiovascular system, such as differentiating between veins and arteries, associating the relationship between the pulse and heart, and that arteries carry blood and not air. Other organ systems that he studied in great detail include the digestive tract and nervous system. He is also said to have performed live dissections on prisoners, although this claim is controversial and not universally accepted.

Herophilus wrote at least nine works, including a commentary on Hippocrates, a book for midwives, and treatises on anatomy and the causes of sudden death, all lost in the destruction of the library of Alexandria (272 CE). Some of it survived through the numerous quotations of his work left by Galen.