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 clumps of blood vessels of the rectum. The hemorrhoidal veins are located in the lowest area of the rectum just above the anus. Sometimes they swell when the veins enlarge and their walls become stretched, thin, and irritated by passing bowel movements.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.