Chitin is a primary component in the exoskeletons of arthropods and crustaceans and is also found in the cell walls of fungi. It's a polysaccharide, and it's excreted by the epidermal cells in arthropods.
Definition & Facts. Hemorrhoids, also called piles, are swollen and inflamed veins around your anus or in your lower rectum. External hemorrhoids form under the skin around the anus. Internal hemorrhoids form in the lining of the anus and lower rectum.
A hemorrhoidectomy is surgery to remove internal or external hemorrhoids that are extensive or severe. Surgical hemorrhoidectomy is the most effective treatment for hemorrhoids, though it is associated with the greatest rate of complications. Hemorrhoid Anatomy Illustration reprinted with permission from the American Society of Colon and Rectal Surgeons. Artist: Russell K. Pearl, M.D. A hemorrhoidectomy is performed in the following settings: 1  Symptomatic grade III, grade IV, or mixed internal and external hemorrhoids. 2  Where there are additional anorectal conditions that require surgery. 3  Strangulated internal hemorrhoids. 4  Some thrombosed external hemorrhoids.