How does the skin protect against UV radiation?

The skin protects against UV radiation primarily by generating melanin, which is a pigment produced by specialized cells known as melanocytes. When the skin is exposed to ultraviolet (UV) light, melanocytes increase melanin production in response to this exposure. The presence of melanin absorbs and disperses UV radiation, which helps to prevent damage to the DNA in skin cells that can lead to skin cancer and other harmful effects.

Melanin acts as a natural sunscreen, providing a protective barrier and reducing the penetration of UV rays into the deeper layers of the skin. This protective mechanism is why individuals with darker skin, which contains more melanin, often have a lower incidence of UV-related skin damage compared to those with lighter skin.

The other options, while related to skin function, do not directly contribute to the protection against UV radiation. Collagen, for instance, provides structural support to the skin but does not specifically act against UV rays. Synthesizing vitamin D is a process that occurs when the skin is exposed to UV light, but it is not a protective mechanism against UV damage. Increasing sweat production is a response to temperature regulation and does not play a role in UV protection.