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 lowest part of your rectum and anus. Sometimes the walls of these blood vessels stretch so thin that the veins bulge and get irritated, especially when you poop. Swollen hemorrhoids are also called piles. Hemorrhoids are one of the most common causes of rectal bleeding. They're rarely dangerous and usually clear up in a couple of weeks. But you should see your doctor to make sure it's not a more serious condition. He can also remove hemorrhoids that won't go away or are very painful.