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.
External hemorrhoids are located underneath the skin that surrounds the anus (lower in the anus than internal hemorrhoids). They can be felt when they swell, and may cause itching, pain, or bleeding with a bowel movement.ymptoms of Prolapsed Internal Hemorrhoids. Prolapse of an internal hemorrhoid occurs when the internal hemorrhoids swell and extend from their location in the rectum through the anus. In the anal canal, the hemorrhoid is exposed to the trauma of passing stool, particularly hard stools associated with constipation.