Which function of the skin protects against UV rays, extreme weather, and bacteria?

Which function of the skin protects against UV rays, extreme weather, and bacteria?

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

Answer: (D)

Protection is the skin’s primary job in guarding you from harm. The outer layer forms a barrier that blocks harmful UV radiation, helps prevent excessive water loss in extreme weather, and keeps bacteria from entering. Melanin in skin cells absorbs UV rays, while the stratum corneum’s tightly bound cells and lipids create a strong physical shield. That same barrier helps moderate moisture and temperature changes, supporting protection against harsh conditions. The skin also maintains an acidic mantle and oil secretions that create an environment unfriendly to many microbes, and immune cells in the epidermis, like Langerhans cells, help fend off invaders. Absorption, secretion, and excretion are real skin activities but describe distinct processes—taking substances in, releasing sweat and oils, and eliminating wastes—rather than the integrated protective barrier described here.

Protection is the skin’s primary job in guarding you from harm. The outer layer forms a barrier that blocks harmful UV radiation, helps prevent excessive water loss in extreme weather, and keeps bacteria from entering. Melanin in skin cells absorbs UV rays, while the stratum corneum’s tightly bound cells and lipids create a strong physical shield. That same barrier helps moderate moisture and temperature changes, supporting protection against harsh conditions. The skin also maintains an acidic mantle and oil secretions that create an environment unfriendly to many microbes, and immune cells in the epidermis, like Langerhans cells, help fend off invaders. Absorption, secretion, and excretion are real skin activities but describe distinct processes—taking substances in, releasing sweat and oils, and eliminating wastes—rather than the integrated protective barrier described here.