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.
Updated February 27, 2017. Hemorrhoids, also known as piles, are swollen and distended veins in the anus and lower rectum. About half of all people over age 50 have hemorrhoids. You are more likely to get hemorrhoids if you strain to have bowel movements or sit for prolonged periods of time on the toilet.