Final answer:
Chemical barriers in the innate immune system, including acidic secretions and enzymes in the skin, stomach acid, and digestive enzymes in the gut, mucus and cilia in the lungs, and antimicrobial agents in tears, saliva, and nasal mucus, protect different body areas from pathogen invasion.
Step-by-step explanation:
Chemical Barriers in the Innate Immune System
The innate immune system employs chemical barriers to protect the body from pathogens. These barriers operate in various parts of the body to destroy or inactivate pathogens, with each area having specific chemical defenses.
- Skin: The skin secretes acids and enzymes like lysozyme through sweat and sebaceous glands, creating an acidic film that discourages pathogenic growth.
- Gut: Stomach acid and digestive enzymes called proteases break down proteins and kill most pathogens that enter the gastrointestinal tract in food or water.
- Lungs: Mucus in the respiratory tract traps pathogens, and cilia help to move contaminated mucus out of the airways.
- Eyes/Nose/oral cavity: Tears, saliva, and mucus contain lysozyme and other antimicrobial agents that act to neutralize pathogens. Mucus in the nose traps and facilitates the removal of pathogens, and saliva in the oral cavity also contains enzymes that destroy pathogens.
These chemical defenses act alongside mechanical and biological barriers to prevent infection by creating an inhospitable environment for pathogens on both body surfaces and within body linings.