ANATOMY

Detailed explanation-1: -These enzymes are called lysozymes . Like stomach acid, they are a form of chemical defence against infection.

Detailed explanation-2: -Chemical barriers against infection include enzymes in tears, saliva and mucus that break down the surface of bacteria.

Detailed explanation-3: -Chemical Barriers Sweat, mucus, tears, and saliva all contain enzymes that kill pathogens. Urine i s too acid ic for many pathogens, and semen contains zinc, which most pathogens cannot tolerate. In addition, stomach acid kills pathogens that enter the GI tract in food or water.

Detailed explanation-4: -Chemical barriers are composed of those sites of the human body where potential pathogens can contact the host cells. A chemical barrier is made up by different proteins that are part of the antimicrobial and immunomodulatory protein/peptide (AMP) family.

Detailed explanation-5: -Gastrointestinal Protectants Gastric acid is a major defense mechanism that prevents many infectious agents from gaining access to the intestinal tract since few bacteria can withstand the low pH of the stomach.