Which of the following is NOT a function of the integumentary system?

• A. Protection against pathogens
• B. Regulation of body temperature
• C. Synthesis of vitamin D
• D. Production of red blood cells

Answer: (D)

Verified step by step guidance

1. Step 1: Begin by understanding the primary functions of the integumentary system. The integumentary system includes the skin, hair, nails, and associated glands. Its main roles are protection, temperature regulation, sensation, excretion, and synthesis of vitamin D.
2. Step 2: Analyze each option provided in the question. For example, 'Protection against pathogens' is a valid function of the integumentary system because the skin acts as a physical barrier to prevent the entry of harmful microorganisms.
3. Step 3: Evaluate 'Regulation of body temperature.' This is another function of the integumentary system, achieved through mechanisms like sweating and vasodilation or vasoconstriction of blood vessels in the skin.
4. Step 4: Consider 'Synthesis of vitamin D.' The skin plays a critical role in synthesizing vitamin D when exposed to sunlight, making this a valid function of the integumentary system.
5. Step 5: Examine 'Production of red blood cells.' This is NOT a function of the integumentary system. Red blood cell production occurs in the bone marrow, which is part of the skeletal system, not the integumentary system.