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.
What are hemorrhoids? Hemorrhoids are normal cushions of tissue containing blood vessels in the lower rectum and around the anus. They are a normal part of the ability to control defecation which helps prevent any leakage of feces. Hemorrhoids affect more than half of the population at some point in their lives.