The body is continually coming into contact with microorganisms and foreign invaders, yet we have a built-in system, called the immune system, to ward these off. The first line of our body’s defense involves any barrier that blocks or prohibits invasion at the portal of entry, and it’s a pretty amazing process.
By creating a physical or chemical barrier, the main function of this line of defense is to stop the invaders from getting into deeper tissues. Parts of the body that are involved in this first line of defense are the skin, mucous membranes, hair follicles, tears, and cilia (tiny hair-like structures). These can play a significant role in the prevention of invasion.
So how does it all work? The skin plays a major role in the protection against harmful substances entering the body. Since the skin provides layers of protection, it is difficult for unwanted invaders to get through this line of defense—as long as it is intact. Unfortunately, if an individual sustains a cut, this serves as a portal of entry for invaders. You may not realize it, but skin glands are also involved in the first line of defense. For instance, when individuals sweat, this creates a “flushing effect” and aids in the removal of organisms. Additionally, blinking, as well as forming tears, can rid the eye of unwanted irritants.
The skin and mucous membranes also produce several chemical defenses which produce a natural antimicrobial effect. Sweat, with its high lactic acid and electrolyte concentrations, also inhibits unwanted invaders. Tears and saliva contain an enzyme called lysozyme, which acts on the cell wall of bacteria, and is believed to play an important role in protecting the eye from infection.
Just as significant is the formation of saliva, which aids in sending microorganisms into the harsh conditions of the stomach. The hydrochloric acid located in the stomach helps to make this organ an unpleasant environment for many pathogens that are swallowed. Similarly, the digestive juices of the intestines are harmful to many microbes as well.
The respiratory tract is also constantly being protected. In fact, even your nose plays a part—as nasal hairs supply assistance by trapping larger particles. The cilia associated with the respiratory tract take care of the smaller particles and microbes by trapping them and moving them to the throat to be expelled or swallowed. Coughing and sneezing are part of the process, too. Foreign matter in the nasal passages causes sneezing; irritants present in the bronchi, trachea, or larynx trigger coughing.
Unfortunately, many microbes and foreign particles find a way to get past these barriers and the body must call upon a process called inflammation, which occurs when tissues are injured by bacteria, trauma, or any other cause.
We all have seen the effects of inflammation. It causes swelling after an injury or causes tissue to redden if a foreign substance invades the body. Here’s what usually happens: the body attacks the invader and any tissue it may have affected, gets rid of it, and then backs off to let healing begin.
It’s an astounding process that protects us and keeps us healthy—that is, unless it goes into overdrive. That’s when problems can arise. In the absence of injury, inflammation can wreak havoc on the body.
Inflammation gone haywire is enough to contend with, but if you add the Western diet and lifestyle to the mix—a diet high in unhealthy sugars, carbs, and fats plus a sedentary lifestyle—then you have an environment conducive for inflammation to get supercharged.
And while there is still much to learn about how our immune systems work, as well as the process of inflammation, there are some practical steps you can take to support overall health.
Losing any excess weight, exercising for about 30 minutes several times a week, eating foods high in antioxidants, such as fruits and vegetables and foods high in omega-3 fatty acids, such as fish, are some of those ways.