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

• A. Tanning
• B. Absorption
• C. Secretion
• D. Excretion

Answer: (A)

Tanning is not a routine function of the skin. The skin’s primary roles include absorption (allowing certain substances to pass into the deeper layers), secretion (releasing sebum from oil glands), excretion (sweat glands helping remove waste products), along with protection, sensation, and temperature regulation. Tanning, on the other hand, is a pigmentary response to ultraviolet light: melanocytes increase melanin production to darken the skin and help shield deeper layers from UV damage. It’s a protective adaptation to UV exposure, not a normal, ongoing function the skin performs in daily physiology.

So the options that describe actual skin processes—absorption, secretion, and excretion—are true functions, while tanning describes a pigmentary response rather than a standard functional activity of the skin.