First Line Body Defence

The first line usually having direct contact with the external environment.

First Lines of Defence~Non specific

1.Skin is an excellent line of defence because it provides an almost impenetrable biological barrier protecting the internal environment.
2.Lysozyme is an enzyme found in tears and saliva that has powerful digestive capabilities, and can break down foreign agents to a harmless status before they enter the body.
3.The clotting of blood near open wounds prevents an open space for antigens to easily enter the organism by coagulating the blood.
4.Mucus and cilia found in the nose and throat can catch foreign agents entering these open cavities then sweep them outside via coughing, sneezing and vomiting.
5.The cell wall of plants consists of fibrous proteins which provide a barrier to potential parasites (antigens).

~~Your body's FIRST LINE OF DEFENSE against germs includes skin, mucous membranes in your nose and throat, tears, the tiny hairs in your nose, bleeding, peeing, and sweating. These protectors either block harmful microbes from entering your body, or wash them away.

~~These first line defenders include the skin and mucous membranes of the respiratory, digestive, urinary, and reproductive systems.

~If these first lines of defence fail, then there are further defences found within the body to ensure that the foreign agent is eliminated.

The Epidermis
The epidermis is composed of multiple layers of tightly packed cells, which few pathogens can penetrate on their own. In addition to this structural barrier, the natural shedding of dead skin cells removes many attached microorganisms.

The Dermis
The dermis is situated beneath the epidermis and contains protein fibers called collagen. Collagen is a tough fibrous protein which gives skin the strength and pliability to resist abrasions that could introduce microorganisms.

Perspiration

Secreted by the skin’s sweat glands, perspiration contains salt and enzymes. Few microbes can live in a highly saline environment, like that of the skin’s surface. The lysozymes in sweat are a type of enzyme that can destroy the cell walls of bacteria.

Sebum
Sebusm is secreted by skins sebaceous (oil) glands. The oil helps keep skin pliable and less likely to break or tear and also lowers the pH of the skin to a more acidic level that inhibits the growth of many types of bacteria.

Defense against infection:

Hydrocloric acid also acts as the body's first line of defense against parasites..in the stomach.

Proper levels of HCI in the stomach are also your first line of defense against bacterial and viral infections.

All day long we unavoidably ingest all kinds of bacteria and viruses through the mouth, nose and food we eat. These germs just cannot survive the trip into the stomach because of it’s the acidic environment. The healthy stomach essentially remains sterile.

Stomach acid levels usually are in the 1 to 3 range, very acidic.