The Lymphatic System and Immunity

Our bodies need to have a defense against all the harmful things that we subject them to.  We need a defense against just the sun alone and all the harmful rays that beat down on us.  In order to maintain a physically healthy body, our bodies require a continuous combat of the harmful agents in our internal and external environments.  

We are constantly being exposed to a variety of pathogens, such as disease-producing microbes that are bacteria and viruses.  Even though our body encounters these everyday, for the most part our bodies remain healthy.  The surface of our body also endures a lot such as cuts and bumps, the exposure to ultraviolet rays, chemical toxins, and minor burns.  Somehow, our bodies seem to be able to fight of these disasters with an array of defenses.  Our body has what is called resistance, and this is the ability to ward off damages or disease through our defenses.  When our bodies don't have resistance, it called susceptibility.  

Our bodies have two general types of resistance, and this is a nonspecific resistance or innate defenses and specific resistance or immunity.  Nonspecific resistance (innate defenses) are present from birth and includes defense mechanisms that provide immediate but general protection against invasion by a wide range of pathogens.  There are mechanical and chemical barriers that help protect our bodies.  These include the barriers of the skin and mucous membranes as the first line of defense in nonspecific resistance.  Another example of this is the acidity if gastric juice kills many bacteria that are present in the food we eat.  

The second line of defense in nonspecific resistance consists of antimicrobial proteins.  these are interferons, complement, and transferrins.  Some other defenses of the nonspecific resistance includes phagocytes, natural killer cells, inflammation, and fever.  For the phagocytes it is mostly the macrophages and neutrophils that are activated.  

Specific resistance, which is immunity, develops in response to to contact with a particular invader.  This means that it only attacks a specific bacteria or virus that is causing harm to our bodies.  It thus occurs more slowly than nonspecific resistance mechanisms and involves activation of specific lymphocytes that are able to fight against that specific invader.  The organ system that is responsible for specific resistance, as well as some aspects of the nonspecific resistance, is called the lymphatic system.  In a sense it works closely with the cardiovascular system, and it also functions with the digestive system in the absorption of fatty foods.  

Even with all these defense systems in place in our bodies, there is still a chance that our bodies are going to come to harm.  It might be able to protect us against some of the harmful pathogens that we encounter, but others no matter how hard our bodies will try and fight it, will eventually get the best of us.  There is also the possibility that our immune system itself will become infected and not function properly.  There are diseases like cancer that will spread to the lymphatic as well, and then it makes it even more difficult for our bodies to fight of any other diseases or infections.