Which glands secrete sebum that helps prevent water evaporation from the skin?

• A. Mucous glands
• B. Sebaceous glands
• C. Eccrine glands
• D. Apocrine glands

Answer: (B)

Sebaceous glands are responsible for secreting sebum, which is an oily substance that plays a crucial role in maintaining skin health. Sebum coats the surface of the skin and hair, forming a barrier that helps to prevent water loss, thereby aiding in skin hydration. This hydration is vital for maintaining the integrity and function of the skin’s protective barrier.

Sebaceous glands are typically found in association with hair follicles, and they become more active during puberty, contributing to the oiliness of the skin in this developmental stage. The presence of sebum not only prevents dehydration but also has antimicrobial properties, helping to protect the skin from pathogens.

In contrast, mucous glands primarily secrete mucous to lubricate and protect mucous membranes, while eccrine glands are sweat glands involved in thermoregulation through the secretion of sweat, which cools the body when evaporated. Apocrine glands, on the other hand, are associated with hair follicles and are involved in scent production rather than moisture retention. Therefore, the primary function of sebum production in sebaceous glands is pivotal for preventing water evaporation from the skin, making them essential for maintaining skin hydration and overall health.