ileum

The Greek verb eilein meant to roll or wind, and Herophilus of Alexandria applied a noun from it, eileon, to the looping final stretch of the small intestine around 300 BCE. Greek physicians had long noticed that this section coiled over itself in the lower abdomen, gathering into loose, writhing knots that resisted neat description. The word carried a physical immediacy that later anatomists found impossible to improve on. Galen of Pergamon, writing around 170 CE, preserved the term in his anatomical surveys and passed it into the Latin medical tradition.

Roman physicians transliterated the Greek into ileum, keeping the sense of torsion but giving it a Latin ending. Celsus, writing around 25 CE, described the intestines in terms borrowed directly from Alexandria, and the coiling lower section traveled through his texts unchanged. The word entered the vast compendium literature of late antiquity, copied and recopied by scribes who rarely knew Greek but trusted the authority of their sources. By the sixth century, ileum was standard in Latin anatomical manuscripts across the Mediterranean.

Medieval Arab physicians, translating Greek and Latin anatomy into Arabic during the ninth and tenth centuries, preserved the concept while adapting the sound. Ibn Sina in his Canon of Medicine (1025 CE) described the intestinal sections with care, and the ileum appeared as a distinct anatomical unit. When European scholars translated the Canon back into Latin during the twelfth century, the word returned to its Latin form and entered university curricula at Salerno and Bologna. The term had circled from Greece to Rome to Baghdad and back to Europe without losing its original meaning.

Andreas Vesalius, dissecting in Padua in 1543, confirmed the term in his De Humani Corporis Fabrica, the landmark that reset European anatomy. He described the ileum as the narrowest and most mobile section of the small intestine, absorbing nutrients and passing waste toward the large intestine. Modern anatomy retains the word without alteration: the ileum runs roughly from the jejunum to the ileocecal valve, where it meets the cecum. The spiral logic of the name holds; this intestine does, in fact, coil.