The immune system protects you from germs and outside “foreign invaders.” Its job is to recognize cells (germs) as foreign or bad for your body and fight them. They kill them, package them up and get them out of your body. Many types of immune cells in a series of reactions makes this happen.
Types of Immunity
There are three types of immunity – innate, adaptive and passive immunity. Each one works with the entire immune system to protect your body.
Innate Immunity
This is your natural immunity – what you are born with. It keeps us from catching illnesses or germs from other animals that are not human. It includes our skin and mucous membranes (like our nose, throat, and gastrointestinal tract). When we get a cut the innate immune system has been compromised. Germs can enter the skin through the cut triggering a different type of immune response.
Adaptive Immunity
This is our active immune system. It is the one we are constantly developing over time. It’s what we expect our bodies to learn over time as we get sick and heal. This part of immunity is related to the lymphocytes (see below). This is also what develops and protects us after a vaccination.
Passive Immunity
This is the final type of immunity. This immunity is temporary. This is what we expect our babies to get through breastmilk. A temporary immunity to the germs the mother was/has been exposed to. This lasts for the early years of the infant’s life.
Components of the Immune System
The immune system is made up of lymph nodes, lymphocytes (B and T), leukocytes (white blood cells), thymus, spleen and bone marrow. This is a very wide overview of the components of the immune system. Our immune system is very complex and each of these components has additional cells and pieces that all play a very complex role in how our system functions. For each disorder the small subcomponents are very important. How they work is researched to find effective cures and treatments for disorders.
Lymph Nodes
These are specialized masses of tissue that filter the lymph that circulates through the lymph system and blood in the body. Lymph nodes are found all through the body in different locations. This helps filter foreign germs and invaders collectively out of the body. The lymph nodes closest to the organ help filter and transfer the clean lymph back to the body. Lymph is a fluid that comes from blood plasma. It is sent to the nodes for filtering to remove bacteria, viruses and other harmful cells like cancer cells. It goes back out to the body to fight infection. The nodes house the B and T lymphocytes after they are created by the bone marrow. These are needed in an immune response (see below).
Leukocytes – White Blood Cells
There are two different categories of leukocytes the lymphocyte and phagocyte. The lymphocytes (see below) recognize, mark and remember germs. Phagocytes are destroyers and eliminators. One example is a neutrophil. The doctor can order blood tests to look at each type of white blood cell and their levels to help determine possible causes for illness.
Lymphocytes – B&T
These are two types of lymph cells produced in bone marrow, both housed in the lymph nodes. B’s job is to tag germs as germs. Then there is a message sent to the T cells to start an attack. What B cells tag are antigens (foreign particles) and then create antibodies for those antigens. The antibody is the memory of that germ. It’s the cell that your body uses in the future to immediately eliminate it if it enters your body. T cells are the killers. They kill the tagged antigens and they are also recruiters. They put a message out for other immune cells to help in the processing of the invaders.
Bone Marrow
Bone marrow is the soft material in the center of long bones in the body. It produces and yellow marrow. Red marrow makes red blood cells, white blood cells, and platelets. Yellow marrow produces fat cells. As a baby most bone marrow produced is red. As a person ages and then turns into an adult there is more yellow marrow. Surrounding this area is where stem cells are produced. Stem cells have the ability to additional cells and tissues. The bone marrow is where the leukocytes are produced. They are then stored in other components of the immune system and body.
Thymus
This organ is temporary in your body. It’s only active until puberty when it then turns off and turns into fat. The effects of its job in that short time last a lifetime. Its job is to protect the body against autoimmunity. Autoimmunity is when the body’s own immune system turns against itself. In autoimmunity, the immune system improperly labels and fights its own body tissues, organs, and systems. Its job is to regular and control the T cells (attackers of germs). The thymus is supposed to prevent this from happening and create healthy T cells.
Spleen
The spleen’s job is to purify and store red blood cells. It contains red pulp and white pulp. The white pulp produces and grows blood cells for the immune system. The red pulps job is to purify the cells and remove dead or malfunctioning cells. It works with the rest of the immune system by keeping the cells clean and pure. It filters out dead or useless cells.
How Does the Immune Work Then?
The skin (or innate portion) protects us from germs entering our body. The innate system can be breached by cut skin or through the mouth or nose. Your body’s B cells tag an antigen and create antibodies to remember it. This prevents it from harming you in the future. The T cells then begin to fight this germ. The phagocytes are called in to clean up the dead cells.
This is a very simplistic version of a very complicated system. There are additional cells and components that work with these main components to accomplish this job. Each has a very particular task to do to keep germs from killing us, or keep our bodies from turning on themselves. Your body is constantly producing and eliminating foreign cells. It is also constantly reproducing new immune cells to continue the fight.
What Happens When the Immune System Doesn’t Work Right?
There are four types of malfunctions that occur. These include allergies, autoimmunity, cancer, and immunodeficiencies.
Allergies
Allergies occur when the body overreacts to allergens that enter the body. The body produces histamines in reaction to the allergens’ presence in the body. The reaction can be mild with a running nose, itchy nose, and watery eyes. Or it can be severe causing anaphylaxis (where the airways swell closed and the person cannot breathe.) This can lead to death if not treated immediately. Most allergies are controlled with antihistamines or specialized medication to control the symptoms. Common allergies today include seasonal allergies, asthma, eczema, and celiac disease.
Immunodeficiencies
These are disorders caused by missing or non-functioning components of the immune system. Most of these are caused by germs or through medication use (acquired). Some people can be born with immunodeficiencies, however (primary). Primary types affect the B, T lymphocytes or the phagocytes. Immunodeficiencies in IgA can cause allergies in children. Some people lack B&T cells altogether leaving them unable to fight any infection. Children can also be born without the thymus gland, or have low or no phagocytes or neutrophils. All making fighting infection or controlling allergies impossible. Secondary or acquired immunodeficiency can be caused by a virus (like HIV) or through the use of certain medications which lower immunity.
Autoimmune Disorders
These are disorders where the immune system fights its own healthy tissues and/or organs. The B cells have improperly labeled healthy cells as antigens. This causes the T cells to attack it’s own body cells, tissues, and/or organs. These attacks on the body can leave permanent and long-term damage. The body’s immunity is also compromised from the confusion and the repeated attacks. The constant attack creates fatigue and possible damage to organs and tissues. The response creates higher levels of inflammation in the body.
Cancers
Cancer is caused by one abnormal cell with incorrect directions. It’s a cell that didn’t get filtered out of the immune system organs. It’s one cell that ends up getting copied incorrectly over and over again until it produces a mass or tumor. The cancer cells can spread to other locations in the body causing a widespread breakdown.
Who Treats Immune System Malfunction?
Rheumatologists and immunologists treat disorders of the immune system. If the diagnosis or outcome is cancer an oncologist would be the physician to treat cancer. Rheumatologists and immunologists focus on treating symptoms associated with each condition, as well as any treatment to alleviate or cure the condition. Most immune system disorders do not have cures. The treatments are focused on decreasing symptoms and preventing flares in the future.
Rheumatologists and immunologists focus on treating symptoms associated with each condition, as well as any treatment to alleviate or cure the condition. Most immune system disorders do not have cures. The treatments are focused on decreasing symptoms and preventing flares in the future.
Resources
Want to learn more about the immune system, its components or treatments, and physicians? Here are some simple and complex online sources. Depending on your comfort level of medical language you can check out each one.
http://www.niaid.nih.gov/topics/immunesystem/Pages/immuneCells.aspx
http://kidshealth.org/en/parents/immune.html#
http://www.news-medical.net/health/What-is-Bone-Marrow.aspx
http://www.endocrineweb.com/endocrinology/overview-thymus