Epithelial surfaces provide the first line of defense against infection by the use of several types of mechanisms. One of the chemical mechanisms used by epithelia is:
A) Joining of epithelial cells by tight junctions
B) Secretion of antimicrobial peptides by epithelial cells
C) Production of mucus, tears, or saliva in the nose, eyes, and oral cavity
D) Movement of mucus by cilia
E) Peristalsis in the gastrointestinal tract

Question

Quizplus · Accepted Answer

Epithelial cells secrete various antimicrobial peptides, such as defensins and cathelicidins, which can kill or inhibit the growth of pathogenic microorganisms. This is an important chemical mechanism used by epithelia to defend against infection.

Epithelial Surfaces Provide the First Line of Defense Against Infection