Integumentary system is an organ system consisting of the skin, hair, nails, and exocrine glands. The skin is only a few millimetres thick yet is by far the largest organ in the body. The average person’s skin weighs 4 KGs and has a surface area of almost 2 square metres. Skin forms the body’s outer covering and forms a barrier to protect the body from chemicals, disease, UV light, and physical damage. Hair and nails extend from the skin to reinforce the skin and protect it from environmental damage. The exocrine glands of the integumentary system produce sweat, oil, and wax to cool, protect, and moisturize the skin’s surface.