Our immune system is made up of cells, organs and vessels. Some of the cells of the immune system are T cells, B cells, and macrophages. T cells are the most important immune cells because they can tell the other immune cells what to do. B cells make antibodies that will stick to germs. Macrophages are swallowing cells that eat germs and other stuff they find in your blood.
Learn more about T cells, B cells, antibodies, or swallowing cells >>
Immune Organs
The organs of the immune system are the spleen, the lymph nodes, and the bone marrow. The lymph nodes are the bumps on your neck that swell up when you get sick! That's where your T cells and B cells multiply and get ready to fight the germ.
Immune Vessels
Just like your blood travels through your blood vessels, your immune cells have their own way of getting around the body. Immune cells travel around our body through our lymph vessels.
In this picture, the lymph vessels and lymph nodes are green. The green bumps that are circled are lymph nodes.
Many organs are involved in the immune response, like the lymphatic system, bone marrow, the spleen, and the thymus.
Bone marrow, the spongy tissue inside of the bone, is the birthing ground for white blood cells. All T cells, B cells, macrophages and others are first created in the bone marrow. B cells mature in the bone marrow, but T cells travel to the thymus to grow.
Just like blood travels through veins and arteries, the cells of the immune system have their own transportation system where they perform many functions. This is called the lymphatic system.
The lymphatic system (highlighted in green) spans the whole body. Nodules, circled above, are lymph nodes where immune cells concentrate and communicate with each other.
The lymphatic system is a network of vessels, lymph nodes, and organs extending throughout the body. The lymph vessels enable a quick mode of transportation for white blood cells and easy connection to lymph nodes and the blood stream. White blood cells like macrophages and T cells concentrate in the lymph nodes, where they can quickly disable any bacteria or virus passing through. Here, B cells divide and multiply, sending a flood of antibodies through the lymph vessels and blood.
Unlike the circulatory system, the lymphatic system lacks a muscle (or organ) that facilitates its movement.
The heart pumps blood throughout the body, but the lymphatic system depends upon the contraction of skeletal muscles for movement. This causes the lymphatic system to move much slower than the circulatory system.
A bad infection will render a lot of activity in the lymph nodes, causing swelling. This is noticeable in some viral infections like Mononucleosis, where the lymph nodes in the neck are swollen and tender.
Stem cells are very important. Right now, scientists are researching how to use these stem cells to help cure diseases like Diabetes.
Read on to Autoimmune Diseases and Diabetes to learn more about stem cells and regenerative medicine!
MM_preloadImages('/sepa/regmed/images/GR_RegenerativeMedicineOn.gif','/sepa/regmed/images/GR_Movies_ON.gif','/sepa/regmed/images/GR_Home_ON.gif','/sepa/regmed/images/GREducationON.gif','/sepa/regmed/images/GR_GamesON.gif'); initializeReadingLevel();
" width="1" height="1" />
