 The tract may also be divided into foregut, midgut, and hindgut, reflecting the embryological origin of each segment.The whole human GI tract is about nine metres (30 feet) long at autopsy.It is considerably shorter in the living body because the intestines, which are tubes of smooth muscle tissue, maintain constant muscle tone in a halfway-tense state but can relax in spots to allow for local distention and peristalsis.