Q: Context: Sebaceous glands are part of the body's integumentary system and serve to protect the body against germs. Sebaceous glands secrete acids that form the acid mantle. This is a very fine, slightly acidic film on the surface of the skin that acts as a barrier to bacteria, viruses, and other potential contaminants that might penetrate the skin. The pH of the skin is between 4.5 and 6.2, and this acidity helps to neutralise the primarily alkaline nature of contaminants.

Question: the sebaceous glands are part of what system? Let's give stream of consciousness first:
The relevant information to answer the above question is: Sebaceous glands are part of the body's integumentary system and serve to protect the body against germs. Therefore, the final answer is integumentary system.