We live in a world full of infectious diseases which are spread through direct transfer of viruses, bacteria or other germs from one individual to another.
The air we breathe is not safe as it contains small particles of diseases like the flu and measles. The food we eat and the water we drink may also be contaminated.
Every day we breathe contaminated air, we come into contact with contaminated surfaces and objects and mingle with people with infection, but we don’t get sick all the time. Have you ever asked yourself why? Well, it’s because of the immune system.
So, what exactly is the immune system?
The immune system is a complex system that protects your body against infectious organisms as well as other invaders. It attacks substances and organisms that invade the system of your body and cause illnesses, through a series of steps famously known as the immune response.
The immune system is made up of special cells, tissues, proteins, and organs that defend human beings against microorganisms and germs every day. According to research, when the immune system is functioning properly, it identifies various threats inclusive of parasites, bacteria, and viruses and distinguishes them from your body’s healthy tissues.
In other words, the immune system is very important as it keeps you healthy and prevents infections and that explains why you can mingle with sick individuals without catching an illness.
Categories of immune system
The immune system can be categorized into innate and adaptive immunity.
Innate immunity is simply the immune system you are born with and comprises of barriers within your body that play a vital role in protecting you from foreign threats. There are several components of innate immunity such as stomach acid, skin, cough reflex, mucus, and enzymes found in tears and skin oil.
Innate immunity also has chemical components such as interferon and interleukin-1. What you should understand is that innate immunity is non-specific and cannot protect against any specific threat. Adaptive, also known as acquired immunity is more complex than innate immunity and targets specific threats to your body.
In adaptive immunity, your body must first process and recognize the threat so that the immune system may thereafter create antibodies designed for that threat.
Once the threat is neutralized, it is recorded by the adaptive immune system and if the same germs try to attack your body in the future, your immune system will respond effectively and fight it.
Functions of the immune system
The major function of the immune system is to keep infectious micro-organisms such as certain bacteria, fungi, and viruses out of the body.
It also destroys infectious microorganisms that invade your body. There are other important immune system functions which we will discuss by examining its main components;
1. Lymphatic system
The lymphatic system is made up of lymph vessels, lymph nodes, and white blood cells.
The role of lymph nodes is to trap microbes, and lymph nodes carry lymph which is a colorless liquid that bathes tissues in your body. The function of the lymphatic system can be summarized as follows;
- Deal with cancer cells
- Manage the levels of body fluid
- React to bacteria
- Absorption of some fats in your diet from the intestine
- Dealing with cell products that may cause disorders or diseases
Spleen is located on the left side of your body, above the stomach and under the ribs. According to experts, the spleen is regarded as a blood-filtering organ whose purpose is to remove microbes and destroy damaged and old red blood cells.
Spleen also makes components of the immune system that fight diseases including lymphocytes and antibodies.
3. Bone marrow
Bone marrow is a spongy, yellow tissue found in the center of the bones. The role of the bone marrow is to produce red blood cells needed by your body to carry oxygen. The platelets are very important for blood clotting and the white blood cells fight infection.
Thymus happens to be one of the most overlooked parts of the immune system. It is situated below the breastbone and monitors and filters your blood content. According to experts, the thymus is responsible for producing white blood cells known as T-lymphocytes.
Immune system disorders
1. Immunodeficiency Disorders
When a part of the immune system is not working properly or is missing, the result is Immunodeficiency Disorder.
This disorder can be acquired through infection, inherited or produced unintentionally for instance through drugs used to treat cancer patients. Temporary immune deficiency can develop as a result of common virus infection such as the flu, measles, and infectious mononucleosis.
The immune response may be depressed by surgery, smoking, blood transfusion, malnutrition, and stress. Some children are born with small or abnormal thymus that lacks T cells, others are born with an immune system that doesn’t function properly, and others have defects in the B cell system and can’t produce antibodies.
2. Autoimmune diseases
The human body consists of a recognition apparatus that distinguishes healthy cells from foreign pathogens.
At times, this apparatus may breakdown in which case your body starts to manufacture antibodies and T cells that are directed against healthy cells instead of faulty cells or foreign pathogens. Autoantibodies and misguided T cells contribute to various diseases such as diabetes when T cells attack the pancreas.
3. Allergic disorders
Your immune system may respond to false alarm leading to allergic disorders. For instance, house dust of grass pollen is considered harmless but to an allergic person, they are mistaken as threats and attacked.
4. Cancers of the immune system
Just like any other cells, immune system cells tend to grow uncontrollably hence leading to cancer.
Leukemia is the most common cancer involving abnormal overgrowth of leukocytes. Another common cancer, especially to children, is lymphoma that involves the lymphoid tissues.
5. Immune complex disorders
When clusters of antigens and antibodies interlock, they lead to immune complexes disorders.
Basically, immune complexes are removed from the bloodstream rapidly but at times, they continue to circulate and get trapped in tissues of the lungs, kidney, joints, skin or blood vessels where they bring out reactions with complement that may lead to inflammation and tissue damage.
The immune system is a complex system made up of special cells, chemicals, and organs that are vital for our survival. It is the immune system that helps you to stay healthy as it defends you against microorganisms and germs every day.
As much as it has an important role in your body, it’s associated with various disorders as illustrated in the article. According to experts, immune system disorders cannot be prevented but you can help it stay stronger by working closely with your doctor.