Although the integument is a covering, it is by no means simple, and some of its functions include ________.
A) the dermis providing the major mechanical barrier to chemicals, water, and other external substances
B) resident macrophage-like cells whose function is to ingest antigenic invaders and present them to the immune system
C) cooling the body by increasing the action of sebaceous glands during high-temperature conditions
D) epidermal blood vessels serving as a blood reservoir
Answer: B) resident macrophage-like cells whose function is to ingest antigenic invaders and present them to the immune system