What is the main function of the integumentary system?

• A. To support blood circulation
• B. To protect the body from external damage and regulate temperature
• C. To assist in digestion and nutrient absorption
• D. To facilitate gas exchange and respiration

Answer: (B)

The main function of the integumentary system is to protect the body from external damage and regulate temperature. This system, which includes the skin, hair, nails, and associated glands, serves as the first line of defense against environmental hazards such as pathogens, chemicals, and physical injuries. The skin acts as a barrier, preventing these harmful elements from entering the body.

Additionally, the integumentary system plays a critical role in thermoregulation. It helps maintain the body's temperature by regulating sweat production and blood flow to the skin. When the body is hot, sweat glands produce sweat, which evaporates and cools the skin. Conversely, when the body is cold, blood vessels in the skin constrict to retain heat.

By combining protective and regulatory functions, the integumentary system is essential for maintaining homeostasis and overall health. The other options mentioned, while related to other body systems, do not encompass the primary purpose of the integumentary system. Blood circulation, digestion, and gas exchange pertain to the circulatory, digestive, and respiratory systems, respectively, rather than the integumentary system.