The function of the integumentary system in humans is to provide a protective barrier for the body. It includes the skin, hair, and nails, serving multiple purposes such as temperature regulation, sensation, and the prevention of water loss. The skin acts as a first line of defense against pathogens and prevents dehydration. Moreover, it plays a vital role in synthesizing vitamin D and allowing for sensory perception through nerve endings. Overall, the integumentary system is essential for maintaining homeostasis and overall health.