Our defense system is made up of entire organs such as the thymus and also vessel systems such as the lymph vessels. However, it is not limited to these specific organs and vessels as it also involves tissues groups and specialized cells throughout the entire body.
To begin our overview of the parts and functions of our immune system, we will look at the three lines of defense it provides:
1) Non-specific Resistance Barriers
Every fortress needs a strong wall to protect it. Thus, our body provides protection through barriers such as our skin, mucous membranes, saliva, and eye fluid (aka, tears). They trap pathogens but also contain substances to kill them. For example, mucous, within our digestive respiratory, urinary, and reproductive tract, contain chemicals that neutralize pathogens. These barriers accomplish tremendous feats to protect our bodies from enemy invaders.
2) Non-Specific Internal “Innate” Immunity
This second line of defense acts as our surveillance team. It includes white blood cells called phagocytes that patrol for and destroy pathogens. Some of these phagocytes include neutrophils and macrophages. Neutrophils are phagocytes that often first respond to the scene. They basically eat pathogens and then self-destruct. As they die off, they create puss. Macrophages, on the other hand, are phagocytes that engulf and digest particles and continue to live.
3) Adaptive Immune System
Last of all, our body has specialized forces that are continually growing stronger as it encounters pathogens, learns their strategies, and determines how to react properly. Because this process is dependent upon environmental exposures, this adaptive form of defense is very weak at birth making infants more susceptible to disease. The unique cells within this system include B-cells and T-cells which have incredible memories that produce antibodies that will fight future invaders.
With this overview of the function of the immune system, we will dive a little deeper next time into many of these specialized cells and organs.
Sources:
Nutritional Therapy Association. “Immune System.” (2014)