The primary purpose of the integumentary system is to protect the body from external threats. This system includes the skin, hair, nails, and associated glands, serving as a physical barrier against pathogens, chemicals, and environmental hazards. Additionally, it plays a crucial role in thermoregulation by helping to maintain body temperature and facilitates the sensation of touch and pain through nerve endings. The integumentary system also aids in vitamin D synthesis when exposed to sunlight, demonstrating its multifaceted role in overall health.