What is the anatomy of the appendix relevant to pediatric appendicitis?

Updated: Oct 25, 2018
  • Author: Adam C Alder, MD; Chief Editor: Carmen Cuffari, MD  more...
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The vermiform appendix is generally 5-10 cm in length. It arises from the cecum, which in most children is located in the right lower quadrant of the abdomen.

Although the base of the appendix is fixed to the cecum, the tip can be located in the pelvis, retrocecal, or extraperitoneal. Note that the anatomic position of the appendix determines the symptoms and the site of tenderness when the appendix becomes inflamed. Because the visceral nerve fibers associated with the appendix typically become inflamed first, there is often vague and referred symptoms to the periumbilical region through the T10 dermatome. As the somatic sensory fibers of the peritoneal lining become involved in the inflammatory process, the pain will frequently shift to the right lower abdomen and tenderness is focused at the site of inflammation.

The appendix is lined by typical colonic epithelium. The submucosa contains lymphoid follicles, which are very few at birth. This number gradually increases to a peak of about 200 follicles at age 10-20 years and then subsequently declines. In persons older than 30 years, less than half that number is present, and the number continues to decrease throughout adulthood. The appendix may act as a reservoir for the flora of the gut which may aid in recovery from intestinal infections. However, this function is not vital for life and removal of the appendix is well tolerated.

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