Protective mechanisms of the body

Abstract: The surface of the body and the openings of the various body cavities (respiratory tract, gastrointestinal tract, genito-urinary tract) are at potential risk from injury and from pathogenic bacteria. The surface of the skin is acidic and inhibits the growth of organisms. Non-pathogenic bacteria (commensals) compete with pathogens for space and nutrients and so inhibit their growth. The openings to the various body cavities are lined with mucous membrane which traps bacteria and other particles. Skin is also shed and mucous is expectorated, but both types of surface produce chemicals which are bactericidal. A second layer of defence is the lymphatic system situated below the body surfaces which drains via regional lymph nodes to the subclavian veins.
Source: Anaesthesia and intensive care medicine - Category: Anesthesiology Authors: Tags: Physiology Source Type: research