Which of the following is NOT a function of the mammalian skin?

Analyze the question: We need the one option that is NOT a function of mammalian skin.

Concept: Functions of mammalian skin

• Protection: against mechanical injury, germs, UV rays and water loss.
• Temperature control: sweat glands, hair erection, and vasodilation/vasoconstriction of blood vessels.
• Excretion: sweat removes water, salts and a little urea.
• Vitamin D production: UV light acts on a cholesterol derivative in the skin to form vitamin D.
• Sensation: receptors for touch, pain, heat and cold.
• Storage: fat is stored in the subcutaneous layer.

Checking each option

• A. Detoxication: this is mainly done by the liver, which breaks down poisons and drugs. It is not a recognised function of the skin, so it is the odd one out.
• B. Excretion: sweating does this, so it is a skin function.
• C. Production of vitamin D: the skin does this in sunlight, so it is a skin function.
• D. Protection: this is a main function of the skin.
• E. Temperature control: the skin does this, so it is a skin function.

Answer: A. Detoxication

Exam tip: Link detoxication with the liver. For "NOT a function" questions, tick off the options you know are true and the leftover one is your answer. For skin, remember P-E-T-S-V: Protection, Excretion, Temperature regulation, Sensation, Vitamin D.