Final answer:
Haustra are the expansible pouches in the colon, resulting from contractions of the teniae coli. They are involved in water absorption and feces formation, contributing to the digestion and excretion processes in the large intestine.
Step-by-step explanation:
Haustra are expansible pouches of the colon, an organ in the digestive system. These pouches are a result of tonic contractions of the teniae coli, which are three bands of smooth muscle found in the large intestine. The teniae coli contract, bunching up the colon into haustra, giving the colon its wrinkled appearance. Haustra are significant for the process of water absorption and feces formation, playing an essential role in the storage and movement of waste through the large intestine. Goblet cells in the lining of the large intestine help ease the passage of feces by secreting mucus. However, haustra do not produce mucus; that is the function of goblet cells. Along with other parts such as the cecum and rectum, the haustra contribute to the large intestine's overall functions of absorption, digestion of materials, and defecation.