Graphic summary of our Immune System

By Sheila Kun RN, BSN, MS, CPN, FCCP

Our immune system is pretty complex. In our previous discussion, we learned about the lymphatic system, the lymphocytes, the T and B cells, the antibodies, interferons, phagocytes, the active and passive immunity. As I have alluded before, it is not an easy system to understand. It would not hurt to go back to the last two weeks’ write up and have a good grasp of the above terms before reading the more in depth summary graph of how our immune system works. I also include some definition of the technical terms so that you can go back to the graph and get a good understanding of this very important system which protects us from getting sick.


Antigen: A substance that stimulates the production of an antibody when introduced into the body. Antigens include toxins, bacteria, viruses, and other foreign substances

Lymphoblast: Immature white blood cell that gives rise to a type of immune cell known as a lymphocyte.

Plasma cell: a fully differentiated B cell that produces a single type of antibody

Complement system: The complement system is a part of the immune system that enhances (complements) the ability of antibodies and phagocytic cells to clear pathogens from an organism. It is part of the innate immune system, which is not adaptable and does not change over the course of an individual’s lifetime.

Clone: The process of immunological B-cell maturation involves transformation from an undifferentiated B cell to one that secretes antibodies with particular specificity. This differentiation and activation of the B cell occurs most rapidly after exposure to antigen by antigen-presenting cells in the reticuloendothelial system, and under modulation by T cells, and is closely intertwined with affinity maturation. B cells that respond most avidly to antigen are preferentially allowed to proliferate and mature, a process known as clonal selection.

*Innate immunity refers to nonspecific defense mechanisms that come into play immediately or within hours of an antigen’s appearance in the body. These mechanisms include physical barriers such as skin, chemicals in the blood, and immune system cells that attack foreign cells in the body.

*Adaptive immunity refers to antigen-specific immune response. The adaptive immune response is more complex than the innate. The antigen first must be processed and recognized. Once an antigen has been recognized, the adaptive immune system creates an army of immune cells specifically designed to attack that antigen. Adaptive immunity also includes a “memory” that makes future responses against a specific antigen more efficient. The adaptive immune system is also known as the acquired immune system.

Source: Wikipedia, *University of Arizona

If the graphic summary is too technical, the cartoon below makes the text on the acquired immunity a little bit easier to understand.

Your homework assignment from the Care Ministry this week: describe the difference between the acquired vs. innate immune system.

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