caecum A pouch in the alimentary canal of vertebrates between the small intestine and colon. The caecum (and its appendix) is large and highly developed in herbivorous animals (e.g. rabbits and cows), in which it contains a large population of bacteria essential for the breakdown of cellulose. In humans the caecum is a vestigial organ and is poorly developed.

caecum The first part of the large intestine, separated from the small intestine by the ileo‐colic sphincter. It is small in carnivorous animals and very large in herbivores, since it is involved in the digestion of cellulose. In omnivorous animals, including human beings, it is of intermediate size. See also gastro‐intestinal tract.

caecum In the alimentary canal of vertebrates, a pouch which in some animals (e.g. Leporidae) contains bacterial populations involved in the digestion of cellulose. In humans the caecum is a vestigial organ and poorly developed.

caecum Dilated pouch at the junction of the small and large intestines, terminating in the appendix. It has no known function in humans. In rabbits and horses, the caecum contains microorganisms which help to break down the cellulose cell-walls of the plants they eat.

caecum (anat.) blind end of the first part of the large intestine. XVIII. — L. (intestinum) cæcum blind (gut), n. sg. of cæcus blind; tr. Gr. tuphlòn énteron.