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 hemorrhoid, also known as a bloody pile, is a swollen vein in or around the rectum. If a hemorrhoid is inside the rectal vault -- rather than outside the anus where they are visible -- it is called an internal hemorrhoid.