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, inflamed veins around the anus or lower rectum. They are either inside the anus or under the skin around the anus. They often result from straining to have a bowel movement. Other factors include pregnancy, aging and chronic constipation or diarrhea.