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A Guide To the Immune System

Health & Immunity:

The importance of the immune system

The immune system is the body’s internal protection system against bacteria, parasites, and illness as well as toxins, environmental stressors and damaged cells.  

With the current increased need for protection against viruses, let’s learn more about the function of the immune system, the cells and tissues involved, and how to better fight off disease.

What Is the Immune System?

There is an innate and an adaptive immune system. The immune system is made up of and supported by leukocytes, or white blood cells. There are a variety of leukocytes, including granulocytes (neutrophils), lymphocytes, monocytes and macrophages. 

These cells travel throughout the bloodstream and lymphatic vessels, seeking out pathogens or foreign entities in the body in order to eliminate any threat to the system. These immune cells are stored primarily in the thymus gland, lymph nodes, the spleen, skin, bloodstream, mucosal tissue, and bone barrow.

 White blood cells fall into two categories: phagocytes, and lymphocytes.

Phagocytes or granulocytes are specialized cells that absorb and break down pathogens and bacteria. Neutrophils, monocytes, mast cells, and macrophages work to perform phagocytosis, remove dead cells, aid in wound healing, and protect the immune system from danger.

The granulocytes are the primary cell of the innate immune system. This is the first line of defense often. Pathogens have certain proteins or molecules that are recognized as dangerous and the neutrophils will engulf them and then destroy them with toxic chemicals.  

The second type of leukocytes is called a lymphocyte, these are found in bone marrow. These cells act as scribes, keeping a record of previously eliminated pathogens in order to recognize them in future attacks. 

T lymphocytes within the thymus either trigger an immune response or take direct action to break down cells that have been compromised, while B lymphocytes in bone marrow produce antibodies in defense against diseases. 

This system requires the ability to present the pathogen on the cell surface, to recognize that pathogen, to clone the immune cell and then to attack cells with that signal from the pathogen. It is very complicated and involves a significant amount of cellular communication.

What Affects Immune Health?

Generally, our immunity becomes stronger as we age because our system is exposed to many pathogens and must learn how to protect against them. Children’s systems are less developed, making them more susceptible to illness. 

Exposure to pathogens effectively trains the immune system. Our society today is likely too ‘clean’ to prepare an immune system for all of the potential pathogens out there.  

Immune disorders can also occur, leaving the immune system weakened against viruses and disease. Immunodeficiencies are often caused by unhealthy lifestyle choices such as malnutrition, or alcoholism, though age can also be a factor. 

Autoimmunity occurs when the body mistakes healthy cells for foreign ones, breaking down necessary and functional protectors within the system.

Lastly, hypersensitivity is a disorder that sprouts from an over-functioning immune system in which the immune response is so strong that it can actually damage the body. All immune disorders have complex sources and many can be treated.


Immunity can be broken down into 4 categories:

  • Innate immunity is the initial system that recognizes threats. This involves white cells that engulf the pathogen and then destroy it. This is a blunt instrument but very effective. However, some pathogens have evolved to avoid destruction by innate immunity. The white cells are able to recognize ‘self’ cells and avoid destroying them usually.

    Most pathogens (bacteria, viruses, parasites, toxic chemicals, etc) produce proteins that are recognized as non-self or dangerous; these are antigens. The complement system is involved in innate immunity as well. Innate immunity also involves the basic barriers that protect us from the environment to include skin, the gastrointestinal lining, cilia, and body hair.  
  • Adaptive immunity refers to the way our system can evolve over time with exposure to antigens to better support the immune system, specifically through the development of antibodies that fight off particular diseases. This also involves T cells that recognize antigens (presented pathogens) and produce clones to attack that pathogen. This is called ‘acquired immunity’ as well.


  • Passive immunity is a short-lived defense from pathogens. This is not naturally occurring in the body but is rather obtained from another source, such as the antibodies transferred via the placenta to the fetus in order to protect against infection.


  • Immunizations are used to strengthen the immune system by means of purposefully introducing a pathogen into the system. The pathogen is a weakened form, allowing the immune system to develop antibodies to protect the system from future viral attacks.

Diet, lifestyle, and the natural makeup of your body can affect the strength of your immune system. Keeping your system functioning optimally is vital to your health, wellbeing, and survival.

Protect Your Immune System

with Well Theory

With our Well Theory Immunity Boost Multi, you can find natural immune support without harsh side effects.

This multi is designed to deliver clinical doses of vitamins D3, C, and a powerful antioxidant boost with 500mg of quercetin. This multi contains higher doses than most available immunity supplements, with herbal ingredients conveniently added to the formulation for unmatched wellness support.


Dr. Meredith Warner is the creator of Well Theory and The Healing Sole. She is a board-certified Orthopedic Surgeon and Air Force Veteran.

She is on a mission to disrupt traditional medicine practices and promote betterment physically, spiritually and mentally to many more people. She advocates for wellness and functional health over big pharma so more people can age vibrantly with more function and less pain.

At Well Theory, Our surgeon-designed products are FDA Registered and formulated to help people:

  • Manage the symptoms of musculoskeletal pain
  • Recover vibrantly from orthopedic related surgeries
  • Fill the gaps in our daily diets
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