QS Study

Positions of Appendix

The appendix is a small, pouch-like sac of tissue that is located in the first part of the colon (cecum) in the lower- right abdomen. When it gets infected, it’s called appendicitis.

It is usually 8 to 10 cm (3 to 4 inches) long and less than 1.3 cm (0.5 inches) wide. It is not clear whether the appendix serves any useful purpose in humans.

Fig: Positions of appendix

Positions of the appendix – It lies in the right iliac fossa. It relates to the anterior abdominal wall, its base is situated at the McBurney’s point. This point lies one-third of the way up the line joining the right anterior superior iliac spine to the umbilicus.

(1) Retrocaecal (Commonest – about 65%) – Appendix lies behind the caecum or colon.

(2) Pelvic (2nd most common – about 30%) – Appendix descends into the pelvis.

(3) Paracolic: Appendix passes upwards and to the right.

(4) Subcaecal: Appendix lies below the caecum.

(5) Preileal: Appendix lies in front of the ileum.

(6) Postileal: Appendix lies behind the ileum.

(7) Promontory: Appendix passes horizontally to the left.

The appendix sits at the junction of the small intestine and large intestine. It’s a thin tube about four inches long. Normally, the appendix sits in the lower right abdomen.