An anatomical pouch is a general term used to describe a small, closed SAC or pouch in the body. The most common example of an anatomical pouch is the BURSA, which is a fluid-filled SAC that acts as a cushion between bones and tendons. SACS are also anatomical pouches, and they are typically filled with air or fluid. Iters are also anatomical pouches, and they are usually found in the digestive system and are filled with digestive juices.