<Tr> <Th> FMA </Th> <Td> 72979 </Td> </Tr> <Tr> <Td_colspan="2"> Anatomical terminology (edit on Wikidata) </Td> </Tr> <P> The integumentary system comprises the skin and its appendages acting to protect the body from various kinds of damage, such as loss of water or abrasion from outside . The integumentary system includes hair, scales, feathers, hooves, and nails . It has a variety of additional functions; it may serve to waterproof, cushion, and protect the deeper tissues, excrete wastes, and regulate temperature, and is the attachment site for sensory receptors to detect pain, sensation, pressure, and temperature . In most land vertebrates with significant exposure to sunlight, the integumentary system also provides for vitamin D synthesis . </P> <P> The skin is the largest organ in the body . In humans, it accounts for about 12 to 15 percent of total body weight and covers 1.5 - 2m of surface area . </P>

What are the two parts of the integumentary system