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 engorged, often painful veins located in your anus. Hemorrhoids can build up in 2 different places. There are 2 distinct branches of veins that drain the blood from the lower rectum and anus.The internal veins can become swollen to form internal hemorrhoids. Internal hemorrhoids, unless they are severe, cannot be seen or felt, unlike external hemorrhoids.Similarly, the external veins can enlarge to form external hemorrhoids. External hemorrhoids can be seen around the outside of the anus and, often, can be felt. Often a simple push of the hemorrhoids back into the rectum can solve the problem. 2  If the hemorrhoids cannot be reduced back into the rectum, then they will continue to inflame and can become trapped outside of the anus. 3  If your hemorrhoids become prolapsed and cannot be reduced, then you will need to see a doctor.