Which glands secrete an oily substance that lubricates and protects the skin?

• A. Eccrine glands
• B. Sweat glands
• C. Sebaceous glands
• D. Endocrine glands

Answer: (C)

Sebaceous glands produce sebum, an oily substance that lubricates the skin and hair and helps protect the skin from drying and minor environmental damage. They are connected to hair follicles and release sebum onto the skin surface. In contrast, sweat glands secrete watery sweat for cooling and waste removal, and endocrine glands release hormones into the bloodstream. So the oily lubrication and protection come from sebaceous glands.