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 swollen veins around the anus. They may be inside the anus (internal hemorrhoids) or outside the anus (external hemorrhoids). Often hemorrhoids do not cause problems. But if hemorrhoids bleed a lot, cause pain, or become swollen, hard, and painful, surgery can remove them.