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.
Sometimes they go away by themselves, but in other cases they can cause lingering pain, itching, and bleeding. There are 2 types of hemorrhoids: those that are just inside the anus or lower rectum (internal) and those that are outside the opening to the anus (external).You can have both at the same time. Internal hemorrhoids usually don't cause pain or discomfort, while external hemorrhoids often do.However, internal hemorrhoids can protrude outside the anus (prolapsed hemorrhoid) and become painful. In some cases, a blot clot (thrombosis) may form in the vein, making the hemorrhoid more painful.nternal hemorrhoids usually don't cause pain or discomfort, while external hemorrhoids often do. However, internal hemorrhoids can protrude outside the anus (prolapsed hemorrhoid) and become painful.