The integumentary system serves as a barrier to protect internal organs from environmental damage, a temperature regulator, an organ capable of vitamin D synthesis, and as an area capable of sensory input. The skin also has minor role in excretion of waste products and hormone production.
The integumentary system is primarily composed of the skin along with hair, nerve endings and sweat glands, all richly supplied by a vast network of capillary beds. The skin is the first line of defense against invading pathogens. Without it, the body rapidly succumbs to massive bacterial and fungal infections. Blind nerve endings lie just beneath the most superficial layer of skin known as the epidermis. They are capable of sensing light touch, temperature, vibration and deep pressure.