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 in the anus or lower part of the rectum. Hemorrhoids are very common. They result from increased pressure on the anus. This can occur during pregnancy, childbirth, and due to constipation. The pressure causes the normal anal veins and tissue to swell. This tissue can bleed, often during bowel movements. Hemorrhoids may be caused by: