Appendix, in anatomy, is a structure attached to a larger or more important part. The term usually refers to the vermiform (wormlike) appendix, a slender, closed tube that extends from the cecum, the first part of the large intestine. The vermiform appendix lies in the lower right part of the abdomen in human beings. It is also found in the higher apes, some rodents, and various other animals. Rats and certain other rodents have a long appendix that functions in digestion. Scientists are not certain what function the appendix has in human beings. Some believe that the appendix may have a role in the development of the immune system or that it may store beneficial bacteria in the digestive system. When inflamed, it causes a disease known as appendicitis. See also Appendicitis .
