The Importance of Natural Immunity: Physical, Chemical, and Biological Barriers That Protect Our Body from Harmful Microbes

Natural-innate immunity

Ability to resist infection by means of normally present body functions. No prior infection. No change in response

Natural or innate immunity is the first line of defense against invading pathogens in our body. It includes physical, chemical, and biological barriers that prevent the entry and spread of harmful microorganisms.

Physical barriers: The first and foremost defense against pathogens is through the physical barriers such as the skin, mucous membranes, hair, and eyelashes. The skin acts as a protective layer against the entry of microorganisms into the body, and the mucous membranes trap and eliminate pathogens.

Chemical barriers: The body uses chemical factors such as sweat, sebum, and stomach acid to kill or inhibit the growth of harmful microorganisms. For example, sweat helps in regulating body temperature, removes microbial populations from the skin surface and sebum possesses antimicrobial properties.

Biological barriers: Our immune system has built-in response mechanisms like phagocytic white blood cells, natural killer cells, and complement system, which aid in destroying the microorganisms that have entered our body.

Phagocytic cells: These cells engulf and digest invading pathogens, thus protecting the body against harmful germs. This process is called phagocytosis.

Natural killer cells: These cells destroy infected body cells by releasing chemicals that cause these cells to rupture.

Complement system: This series of proteins present in the blood help in opsonizing, attaching antibodies to bacteria and thus making it easier for phagocytic cells to destroy them.

In conclusion, the body’s natural or innate immunity response is an essential first-line defense mechanism. These physical, chemical, and biological barriers protect the body from pathogenic microorganisms and keep the body healthy and protected.

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