How does the immune system work? What organs make up the Immune System?

October 25, 2017

The tonsils, lymph nodes, thymus, spleen, Peyer’s Patches, lymphatic vessels and bone marrow make up the immune system organs.

This is Dr. Jim for Be Healthy! Be Happy! College of Immune Health – Immune Health 101: The Organs.

The immune system functions as an integrated network of organs, specialized cells and unique bodily fluids. In this segment, I discuss the organs – the tonsils, lymph nodes, lymphatic vessels thymus, spleen, Peyer’s Patches, lymphatic vessels and bone marrow that make up this complex system.

First, the tonsils. Often viewed as the front line of defense against invading viruses and bacteria, the tonsils lie in the back of the throat to fight off the entrance of germs causing infections like mononucleosis and strep throat. Enlarged tonsils may cause problems requiring surgical excision. Fortunately, over all immune function is not substantially impaired following removal.

Next, the lymph nodes. Lymph nodes are found all over the body. Lymph nodes work to filter and trap destroyed bacteria, viruses, parasites and tumor particles rendered powerless by other components of the immune system.

Connected to the lymph nodes are the lymphatic vessels, which parallel the circulatory system and provide a network of conduits to distribute the anti-bodies, antigens and anti-toxins produced by the immune system and so necessary for just in time immune system response.

The thymus gland lies in the center of the chest between the throat and the heart. It is especially prominent in children and functions to coordinate immune response and promote development of immune system memory also known as acquired immunity.

The spleen is an abdominal organ and found in the left upper quadrant of the abdominal cavity. The spleen acts as an immune system filter and is not necessary for overall immune system function, however, following removal, infections from pneumonia and meningitis are more common if patients don’t follow vaccination recommendations.

Peyer’s Patches constitute a network of lymphatic tissue spread throughout the small intestine. Peyer’s Patches monitor intestinal bacteria and block the growth of harmful germs in the GI tract.

Finally, the bone marrow. The bone marrow is responsible for the production of the cellular components of the immune system. These cells called neutrophils, eosinophils, basal cells, monocytes, macrophages and lymphocytes which will be the subject of my next Immune Health 101 conversation.

This is Dr. Jim for Be Healthy! Be Happy! hoping that this message powers your path to happiness!

References: Oregon State University Linus Pauling Institute Micronutrient Information Center. Online [available at]: