What is the substance that is secreted by the oil glands?

The substance secreted by the oil glands in the skin is sebum. Sebaceous glands produce sebum, which is an oily substance composed mainly of lipids. Its primary function is to lubricate and protect the skin and hair, keeping them hydrated and preventing the loss of water. Sebum also has antimicrobial properties, helping to protect the skin from infection.

Collagen, keratin, and hormones do not serve the same function as sebum. Collagen is a structural protein that provides strength and elasticity to the skin, keratin is a protein that helps form the outer layer of skin and creates barriers, and hormones are signaling molecules that regulate various bodily functions but do not directly relate to the lubrication and protection of skin provided by sebum. Understanding the role of sebum emphasizes its importance in maintaining skin health and its protective barrier, distinguishing it from other substances produced in the body.