What is one primary function of sebaceous glands?

The primary function of sebaceous glands is to produce an oily substance known as sebum, which plays a vital role in maintaining the health of the skin and hair. Sebum serves to lubricate and waterproof the skin and hair, helping to prevent dryness and brittleness. This oily secretion has antimicrobial properties, contributing to the skin's barrier defense against pathogens. By keeping the skin moisturized, sebaceous glands play an essential role in preserving the integrity and elasticity of the skin, which can be particularly important in preventing skin irritation and conditions such as eczema.

The other options illustrate different functions of skin and its components but do not pertain to sebaceous glands. For instance, the secretion of sweat for temperature regulation is primarily a function of sweat glands. UV protection is generally managed by the pigment in the skin (melanin) rather than sebum, while detecting changes in temperature is a function of sensory receptors in the skin rather than a role of sebaceous glands.