What is the oily secretion produced by the sebaceous glands?

The oily secretion produced by the sebaceous glands is known as sebum. Sebum plays a crucial role in maintaining the health and integrity of the skin and hair. It serves to lubricate and protect these structures, preventing them from becoming dry and brittle. The presence of sebum also contributes to the skin's barrier function, helping to keep moisture in while safeguarding against external environmental factors that could cause irritation.

Sebum is composed mainly of triglycerides, wax esters, and squalene, making it an effective moisturizer. Its production is influenced by various factors, including hormones, which is why some individuals may experience increased oiliness during puberty or hormonal fluctuations.

Perspiration refers to the secretion of sweat from sweat glands, which is primarily responsible for regulating body temperature and excreting waste products. Keratin is a fibrous protein that forms the structural framework for hair and nails, contributing to their strength but not related to oily secretion. Collagen is a protein that provides structural support and elasticity to the skin, but it is not secreted by the sebaceous glands. Hence, sebum is the correct answer for the secretion produced by these glands.