The appendiceal wall has a similar tissue structure to the colon, and the appendiceal mucosal epithelial cells secrete a small amount of mucus. The appendix is a lymphoid organ involved in the production and maturation of B-lymphocytes and has some immune function. The wall of the appendix is rich in lymphoid tissue, which is thought to be useful in preventing infections such as viruses by producing lymphocytes and antibodies together with Peyer’s lymphoid follicles at the end of the ileum. The lymphoid tissue of the appendix begins to appear after birth, peaks at the age of 12-20 years with more than two hundred lymphoid follicles, and then gradually decreases, with the follicles decreasing significantly after the age of 30 years and disappearing completely after the age of 60 years. Acute appendicitis is a common and most frequent acute abdominal condition in surgery. The appendix is prone to inflammation because of its own anatomical characteristics. Its anatomical structure is a slender blind tube with a lumen rich in microorganisms and a rich lymphatic tissue in the intestinal wall, which makes it prone to infection.