Physical and Chemical Barriers (Innate Immunity) Physical and chemical barriers form the first line of defense when the body is invaded. Physical Barriers. The skin has thick layer of dead cells in the epidermis which provides a physical barrier. Periodic shedding of the epidermis removes microbes.
Explanation
Physical and chemical barriers form the first line of defense when the body is invaded. The skin has thick layer of dead cells in the epidermis which provides a physical barrier. Periodic shedding of the epidermis removes microbes. The mucous membranes produce mucus that trap microbes.
