Erasistratus, considered the father of physiology, was born on the island of Chios in ancient Greece. His father and brother were doctors, and his mother was the sister of a doctor. He studied medicine in Athens and then, around 280 b.c., enrolled in the University of Cos, a center of the medical school of Praxagoras. Erasistratus then moved to Alexandria, where he taught and practiced medicine, continuing the work of Herophilus. In his later years, he retired from medical practice and joined the Alexandrian museum, where he devoted himself to research.

Although Erasistratus wrote extensively in a number of medical fields, none of his works survive. He is best known for his observations based on his numerous dissections of human cadavers (and, it was rumored, his vivisection of criminals, a practice allowed by the Ptolemy rulers). Erasistratus accurately described the structure of the brain, including the cavities and...