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.
Hemorrhoid Overview. Hemorrhoids are enlarged veins located in the lower part of the rectum and the anus. The veins become swollen due to increased pressure within them, usually from constipation or profuse diarrhea, and during pregnancy because of the pressure of the enlarged uterus.Internal hemorrhoids are located in the inside lining of the rectum and cannot be felt.he veins become swollen due to increased pressure within them, usually from constipation or profuse diarrhea, and during pregnancy because of the pressure of the enlarged uterus. Internal hemorrhoids are located in the inside lining of the rectum and cannot be felt.