32.3 The Integumentary System – We learned that the dermis is the thick inner layer of skin that contain structures that interact with other body systems to maintain homeostasis by regulating by temperature. Sebaceous glands in the dermis secrete sebum which is an oily acidic substance. Sebum keeps the epidermis flexible and waterproof and kills bacteria. We learned about internal and external factors that affect the health of the skin. We discovered how acne, hives, and skin cancer affect the skin.