A Healthy Immune System…a very brief look (part 1)


healthy cell boxThe body has a remarkable way of defending itself against disease causing agents: our Immune System. Let’s take a quick peek at all of the ways it keeps us healthy…The immune system protects us from disease causing pathogens, foreign microorganisms that invade our body and from our own cells that have become malignant or cancerous.  The immune system is made up of the basic building block of the body: cells that have differentiated into their specialized form.  The immune system includes our skin barrier, mucous membranes located in our nose, mouths, tonsil, adenoids, and gut.  It also includes our lymph system and blood.  Cells formed in the bone marrow are red blood cells, white blood cells and platelets.  When the body encounters a germ, it activates the immune system.  The specialized cells and organs of the immune system recognize and respond to foreign invaders.

The organs of the immune system include the thymus which is a lymphoid organ located very close to the heart and it teems with lymphoid cells, macrophages and epithelial cells.  Pre-T cells are produced in the bone marrow and travel to the thymus to mature and learn to differentiate between ‘self’ and ‘non-self’.  The thymus secretes a group of hormones called “thymosin”.  Large numbers of lymph vessels are present in the thymus.

The secondary lymph organs are the lymph nodes which act as a filter and drain of the fluids from most of our tissues; this process captures antigens and presents them to T and B cells, which then initiates an immune response. The spleen filters and traps antigens in the circulating blood in a similar way to the lymph nodes.

Bone marrow is the soft tissue with in the bones where blood cells are made.  All blood cells begin in the bone marrow as stem cells which are immature cells.  When the need arises, these stem cells are signaled to develop into red blood cells, white blood cells or platelets.

Red Blood Cells (RBC) carry oxygen and carbon dioxide throughout the body.  Hemoglobin is the part of the RBC that carries oxygen; the body’s tissues need oxygen to function properly.  RBC counts are stable when the bone marrow is working normally- anemia occurs when there are too few RBCs in the body.  A side effect of leukemia or chemotherapy may be anemia.

White Blood Cells (WBC) include several types of cells and each has a separate role in protecting the body from germs.  The WBCs increase the body’s resistance to infection and conversely, infections are more likely to occur when there are too few normal WBCs.

  • Phagocytes are WBCs derived from bone marrow. 2 of the many types of WBCs are neutrophils and monocytes that migrate out of the blood and into the tissues in response to infection.  Microphages “wander” through the tissue devouring bacteria or microorganisms and some microphages become residents of other organs.
  • Lymphocytes are the most numerous cells of the immune system and are responsible for antibody production. Lymphocytes arise from primitive cells in the bone marrow called stem cells.  They circulate in the body fluids, tissue, lymph, thymus, spleen and liver.  B-cells help produce humoral immunity to which is the resistance to disease organisms made by the actions of antibodies binding to antigens while circulating in body fluids.  T-cells are lymphocytes that have undergone their first stage of development in the thymus gland.

Platelets are the blood cells that help control bleeding; they collect at the injury site and form a plug to stop the bleeding.

to be continued…Enhance your health; it’s a precious gift and thanks for checking in,

Jane Ann, CMT 54206

 

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