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 located around the anus or in the lower rectum. About 50 percent of adults experienced the symptoms of hemorrhoids by the age of 50. Hemorrhoids can either be internal or external. Internal hemorrhoids develop within the anus or rectum. External hemorrhoids develop outside of the anus. Hemorrhoids are also known as piles. External hemorrhoids are the most common and most troublesome. Hemorrhoids cause pain, severe itching, and difficulty sitting.