Question

Which of your body’s nonspecific host defenses would help fights pathogen entering your body through each of the following portals? A small cut on your hand; inhalation into your lungs; ingestion of contaminated food.

Answer 1

there are several nonspecific immune defense mechanisms to counteract the evasion by foreign particles such as

anatomical barriers (skin and mucous membrane),

physiological barriers (temperature, low pH, and chemical mediators such as lysozyme, interferons, complement lysis, Toll-like receptors, collectins, etc),

phagocytic or endocytic barriers (blood monocytes, neutrophils, macrophages) and

inflammatory barriers (redness, swelling, heat, pain)

a small cut in hand- inflammation

tissue damage induces leakage of vascular fluid, containing serum proteins with antibacterial activity and influx of phagocytic cells to the affected area.

inhalation into lungs- mucous membrane of lungs

mucous membrane entraps foreign microorganisms. cilia propel microorganisms out of the body.

ingestion of contaminated food- low pH

the acidity of stomach kills most of the ingested microorganisms.