What is the primary function of the integumentary system?

• A. Regulate body temperature
• B. Protection
• C. Facilitate movement
• D. Produce hormones

Answer: (B)

Protection is the primary function of the integumentary system. The skin acts as a tough, flexible barrier that blocks pathogens and minimizes water loss, which helps keep internal tissues safe and hydrated. The outer epidermis provides waterproofing, while cells in the skin contribute to immune defense, helping to detect and respond to invaders. Melanin helps shield underlying tissues from UV radiation, adding another layer of protection. Temperature regulation and sensation are important roles the skin supports, but they are secondary to its job of safeguarding the body from injury, infection, and dehydration. Movement comes from the musculoskeletal system, and hormones come from endocrine glands, not the skin.