appendix

 

appendix - A small, narrow tube that projects out of the caecum (the 1st part of the colon) at the lower right-hand side of the abdomen. It may lie behind or below the caecum, or in front of or behind the ileum (part of the small intestine).

The appendix has no known function, but it contains a large amount of lymphoid tissue which provides a defence against local infection. The position of an individual’s appendix partly determines the set of symptoms produced by acute appendicitis (inflammation of the appendix).