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 hemorrhoids are often painless but they sometimes cause a lot of bleeding. The internal veins may stretch and even fall out (prolapse) through the anus to outside the body. The veins may then become irritated and painful. emorrhoids are swollen veins and tissue in the lower rectum and anus. The anus is at the end of the rectum and is the opening through which bowel movements pass from your body. Hemorrhoids are a common problem. Another name for them is piles.