Surface barriers, such as cutaneous and mucous membranes, serve the immune system as the:
A) third line of defense.
B) first line of defense.
C) second line of defense.
D) fourth line of defense.

Question

Quizplus · Accepted Answer

Surface barriers like cutaneous and mucous membranes are considered the first line of defense in the immune system, providing a physical barrier to prevent pathogens from entering the body.

Surface Barriers, Such as Cutaneous and Mucous Membranes, Serve the Immune