Appendicitis

- Cramping type of pain frequently occurs in appendicitis.
- An inflamed appendix exhibits what is called dual transmission of pain. Pain impulses pass first from the appendix through visceral pain fibers located within the sympathetic nerve bundles, and then into the spinal cord at about T10 or T11; this pain is referred to an area around the umbilicus and is of the aching, cramping type.
- Pain impulses also often originate in the parietal peritoneum where the inflamed appendix touches or is adherent to the abdominal wall.  These cause pain of the sharp type directly over the irritated peritoneum in the right lower quadrant of the abdomen.
- Located at McBurney's Point.
- Mesoappendix is the site of the appendicular artery.  Thrombosis of this artery can occur from accumulation of fecal matter in the appendix.
- In appendicitis the appendicular artery ultimately thromboses.  When this occurs, gangrene and perforation of the appendix inevitably supervene.

- Appendicectomy is performed most commonly through a grid-iron muscle-splitting incision.  The appendix is first located and then delivered into the wound.  The mesentery of the appendix is then divided and ligated.  The appendix is then tied at its base, excised and removed.  Most surgeons still opt to invaginate the appendix stump as a precautionary measure against slippage of the stump ligature.


Reference:
1. Guyton, Arthur C., & Hall, John E. Textbook of Medical Physiology 11th Edition. 2006.