Question

a pathogenic bacteria lands on your forearm. what happens first? a white blood cells in the skin phagocytize the pathogens. b the skin acts as a protective barrier, keeping the pathogen out. c mucous membranes use enzymatic activity to destroy the pathogen. d the adaptive immune response is alerted in case it is needed.

Explanation:

The skin is the first - line of defense against pathogens. When a pathogen lands on the skin, the skin acts as a physical barrier to prevent the pathogen from entering the body. Phagocytosis by white blood cells, action of mucous membranes, and activation of the adaptive immune response occur later if the pathogen manages to breach the skin barrier.

Answer:

B. The skin acts as a protective barrier, keeping the pathogen out.