1) resistance to trauma and infection (packed with tough keratin and linked by strong desmosomes that give this epithelium its durability)
2) other barrier functions (prevents body from absorbing and losing water and the epidermis protects against uv rays)
3) vitamin D systhesis which is needed for bone development and maintenance. The liver and kidneys complete the process
4) sensation. The skin is our most extensive organ. It has a variety of nerve endings that react to heat, cold, touch, texture, pressure, vibration, and tissue injury. Especially abundant on the face, palms, fingers, soles, nipples, and genitals, but few on the knees and elbows
5) thermoregulation - it responds to overheating by cutaneos vasodilation and to chilling by cutaneous vasoconstriction. The skin plays roles in both warming and cooling the body
6) nonverbal communication - skeletal muscles insert in the dermis and pull on the skin to create subtle and varied facial expressions.