Final answer:
Sebaceous glands are a part of the integumentary system and produce sebum to lubricate and waterproof the skin and hair.
Step-by-step explanation:
Sebaceous glands are a part of the integumentary system.
They are responsible for producing and excreting sebum, an oily substance that lubricates and waterproofs the skin and hair.
Sebaceous glands are found all over the body, with the highest concentration on the face and scalp.