Many other common diseases are caused by autoimmunity such as juvenile diabetes and low thyroid disease. It has been recently discovered that some persons who suffer with hives or angioedema also have an autoimmune disease. In these cases, autoantibodies have been formed that bind to the Fc-receptor on mast cells.
Lesson Summary. 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. But, it can't grow with the animal, so shedding becomes necessary.
1 chitin Hard and tough natural material made from glucose molecules joined together. 2  Chitin is found in cell walls of fungi and in the exoskeletons of arthropods. 3  chloroplast Contains the green pigment chlorophyll; the site of photosynthesis. cell Basic unit of life. 2  Unicellular organisms only have one cell. 3  Multicellular organisms have many cells. 4  chitin Hard and tough natural material made from glucose molecules joined together. 5  Chitin is found in cell walls of fungi and in the exoskeletons of arthropods.