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.
Internal Hemorrhoid â A swollen vein inside of the anal canal. Internal hemorrhoids often are small, but they can be large and bulge out of the anus. If they bulge out and are squeezed by the anal muscles they can be particularly painful, even more so if the muscle cuts off the hemorrhoids blood supply.