Praxagoras of Cos

Praxagoras was a Greek physician from the island of Kos (fl. end of the fourth century–beginning of third century BCE).

Born in an island with huge medical tradition in ancient Greece, Praxagoras of Cos became an esteemed medico-philosopher and surgeon. The evolution made by the Hippocratic School of Medicine further boosted his talent and helped him perform surgical operations, which were believed impossible for his era.

The theories of Praxagoras of Cos and his followers constitute an important landmark in the history of ancient medical knowledge.

Praxagoras of Cos, influenced by Aristotle, adhered to cardiocentrism and considered the heart as the seat of the soul, of thought and psychic functions, a belief seen also in Ancient Egypt.

He is reported to distinguish between the vessels stemming from the aorta (arteries), on the one hand, and the vessels stemming from the vena cava (veins), on the other, and to separate these types of vessels as if they form two distinct systems.

Praxagoras suggesting that there were in the body miniscule arteries that were responsible for transmitting signals through the body. Some arteries became so thin at their endings that their lumen (koilotès) virtually disappeared. For this final part he used the word “neuron” (νεῦραν), which was the Greek word for ‘cord’ or ‘sinew’.

He also introduced an innovative surgical technique to confront small bowel obstruction, by creating an enterocutaneous fistula.
Praxagoras of Cos