Pathogenic microbes are found on the skin, respiratory tract, mouth, vagina and the intestinal tract;
The skin; has a keratinised and waterproof cornified outer layer; that provides a mechanical barrier to microbes/prevents entry of microbes.
Sebaceous gland; produces sebum; which has antiseptic properties.
The respiratory tract; produce mucus secretions that trap dust.
Cilia sweep/waft/propel the microbes to the pharynx for swallowing or to be coughed out;
Reflex actions of coughing/sneezing/vomiting help remove foreign materials from the respiratory tract/digestive tract;
Lysozymes/enzymes in saliva/nasal secretions/tears; digest walls of bacteria destroying them.
Gastric secretions such as hydrochloric acid lowers the pH in the stomach killing micro-organisms;
Clotting of blood; prevents entry of microbes after damage of blood vessels.
Phagocytosis; by phagocytes engulf and destroy microbes and other foreign bodies.
Lymphocytes are stimulated to produce antibodies; by proteins present in microbes protecting the body;
Antibodies destroy/kill micro-organisms through various ways:
Agglutinins; bind to pathogens making them clump together; killing them;
Lysins; bind to pathogens and make them burst or disintegrate;
Opsonins; bind to pathogens making them easily recognized hence be engulfed/destroyed by other lymphocytes;
Anti-toxins; bind and neutralize toxins produced by micro-organisms;
Vagina is acidic; hence making it not conducive for growth and reproduction of micro-organisms;
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