Digestive System

Digestion in the cockroach takes place along an alimentary canal divided into three functional regions - foregut, midgut and hindgut. The foregut (pre-oral cavity, mouth, pharynx and oesophagus) leads into a sac-like crop that stores swallowed food, followed by the gizzard (proventriculus), whose thick circular muscles and six chitinous internal plates ("teeth") grind the food mechanically. The short, glandular midgut lies just behind the gizzard and bears eight finger-like hepatic (enteric) caecae at its junction with the foregut, which secrete digestive juices along with the midgut's own glandular cells. The hindgut, broader than the midgut, is where 100-150 fine, yellow Malpighian tubules attach and remove nitrogenous waste from the haemolymph; the hindgut itself is further divided into the ileum, colon and rectum, with the rectum opening to the outside through the an …