What is the function of the skin in the integumentary system?
A. Oxygen transport
B. Hormone secretion
C. Protection and regulation
D. Blood filtration
Answer (1)
The answer is C. Protection and regulation The skin is the largest organ in the human body and plays a central role in the integumentary system, which also includes hair, nails, and various glands. Its primary functions are protection, temperature regulation, sensation, vitamin D production, and excretion.Protection: The skin acts as a physical barrier against harmful microorganisms (like bacteria and viruses), UV radiation, toxic chemicals, and mechanical injury. The outermost layer — the epidermis — is composed of keratinized cells that are water-resistant and tough.Thermoregulation: Through sweat glands and blood vessels, the skin helps regulate body temperature. When it’s hot, we sweat, and blood vessels dilate to release heat. In cold weather, blood vessels constrict to conserve heat.Sensation: The skin is rich in nerve endings that detect touch, pain, pressure, and temperature, making it an essential sensory organ.Vitamin D synthesis: When exposed to sunlight, the skin helps produce vitamin D, which is important for calcium absorption and bone health.Excretion: Through sweat, the skin can excrete small amounts of waste products like urea and salts.The skin has three major layers:Epidermis – outermost layer; protective.Dermis – contains blood vessels, sweat/oil glands, hair follicles, and nerves.Hypodermis (subcutaneous tissue) – made of fat and connective tissue; provides insulation and energy storage.To clarify:Oxygen transport is the role of red blood cells.Hormones are secreted by glands in the endocrine system.Blood filtration is the job of the kidneys.By learning how the skin works, students better understand why it’s important to protect it from sun damage, injury, and infection. It also shows how the body interacts with the environment.
