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.
Hemorrhoids are a collection of nerves, connective tissue, veins and arteries in the anal wall that often enlarge over time and cause severe pain and discomfort. In certain cases hemorrhoids prolapse, or fall outwards from the anus, which increases the pain associated with the condition.