How does the immune system protect the body from disease?

What comprises your immune system, and what is its role?

The immune system defends your body against substances it sees as foreign or harmful. These substances are known as antigens. The immune system comprises particular organs, cells, and chemicals that help fight infection (or microbes). The significant parts of the immunity system are:

  • Antibodies.
  • The complement system.
  • White blood cells
  • The thymus
  • The spleen
  • The lymphatic system.
  • The bone marrow.

These parts of the protected actively fight against infections or diseases. There are two significant subsystems of your immunity system:

  • The adaptive immunity system. When your body is exposed to the microbes or chemicals released by microbes, you develop this.
  • The innate immune system. You are born with this. These two immune systems work together.

The adaptive and innate immune system

These are two subsystems of the immune system, called the innate (or non-specific) immune system and the adaptive (or specific) immunity system. Both of these subsystems of the immune system are closely linked and act together whenever a harmful substance or germ triggers an immune response.

The innate immune system offers a general defense against harmful substances and germs, so the innate immune system is also known as the non-specific immune system. It primarily fights using immune cells like natural killer cells and phagocytes (or “eating cells”). The vital job of the innate immunity system is to fight against harmful substances and germs that enter your body, for example, through the digestive system or skin.

The adaptive (or specific) immune system prepares antibodies and uses the antibodies to specifically fight the germs that our body has previously come into contact with. This is also called an “acquired” (or learned) or specific immune response. Because the adaptive T-cells constantly adapts and learns, your body can also fight viruses or bacteria that change over time.

How does your immune system work?

The immune system has a crucial role: It protects your body from germs, harmful substances, and cell changes that can make you ill. The immunity system comprises various organs, proteins, and cells.

As long as the immune system is running smoothly, you do not notice that it is there. But if the immunity stops working properly – because it is weak or can not fight against particularly aggressive germs – you get ill. Germs that the body has never encountered previously could also likely make you fall sick. Some germs will only make you ill for the first time you come into contact with them. These include childhood diseases such as chickenpox.

The tasks of the immune system

Without an immune system, you would be unable to fight harmful things that enter your body from the outside. The immunity system also fights the dangerous changes that occur inside your body. The main tasks of your body’s immune system are

  • to fight disease-causing germs (or pathogens) like viruses, parasites, bacteria, or fungi, and to discard them from your body,
  • to identify and neutralize harmful things from the environment, and
  • to fight disease-causing changes in your body.

How is your immunity system activated?

The immune system gets activated by various things that your body does not recognize as its own. These are known as antigens. Examples of antigens are the proteins on the surfaces of fungi, bacteria, and viruses. When the antigens attach to special receptors on your immune cells (or immunity cells), it triggers a series of processes in your body. When the body comes in close contact with a particular disease-causing germ for the first time, it stores information regarding the embryo and how to fight against it. Then, if your body comes into contact with the germ again, it identifies it straight away and starts fighting it faster.

Your body’s cells have proteins on their surface, too. But those proteins do not usually trigger the T-cells to fight the cells. Sometimes the immunity system mistakenly thinks that your body’s cells are foreign. The immunity system then attacks harmless and healthy cells in the body. This is known as an autoimmune response.

The T-cells and microbial infection

Your immune system records every microbe it has ever defeated in types of WBCs or white blood cells (T- and B-lymphocytes) called memory cells. This means it can identify and destroy the microbe quickly if it enters your body again before it can multiply and make you ill. Some infections, such as the common cold and flu, have to be fought several times because various viruses or strains of the same virus may cause these illnesses. Catching the flu or cold from one virus doesn’t give you immunity against the others.

What are the significant parts of the immune system?

Following are the main parts of your immunity system are:

White blood cells

White blood cells or WBCs are the key players in your T-cells. WBCs are made in your bone marrow and are part of your lymphatic system. WBCs move through blood and tissue throughout your body, searching for foreign invaders (or microbes) such as bacteria, parasites, viruses, and fungi. When the WBCs find them, they launch an immune attack.


Antibodies help your body fight microbes or the toxins (or poisons) they produce. They identify substances known as antigens on the microbe’s surface or in the chemicals they make, which mark the toxin or microbe as foreign. The antibodies then mark the antigens for destruction. There are several proteins, cells, and chemicals involved in this attack.

Lymphatic system

Your lymphatic system is a network of delicate tubes throughout your body. The significant roles of the lymphatic system are to:

  • React to bacteria.
  • Manage the fluid levels in your body.
  • Absorb some of the fats in your diet from the intestine.
  • Deal with cell products that otherwise could result in disease or disorders.

The lymphatic system comprises of:

lymph nodes (also known as lymph glands) trap microbes

lymph vessels are tubes carrying lymph, the colorless fluid that bathes the tissues of your body. The lymph vessels contain infection-fighting WBCs white blood cells.


The spleen is a blood-filtering organ that works to remove microbes. The spleen also destroys damaged or old red blood cells. The spleen also makes disease-fighting components of the immune system (including lymphocytes and antibodies).

Complement system

The complement system comprises proteins whose actions complement the work done by antibodies.


The thymus filters and monitors the blood content. It produces the WBCs called T-lymphocytes.

Bone marrow

Bone marrow is a spongy tissue in our bones. Bone marrow produces the RBCs or red blood cells our bodies require to carry oxygen, the WBCs we use to fight infection, and the platelets we need to help our blood clot.

5 thoughts on “How does the immune system protect the body from disease?

  1. The very next time I read a blog, I hope that it doesn’t disappoint me just as much as this one. After all, Yes, it was my choice to read, but I really believed you’d have something useful to talk about. All I hear is a bunch of crying about something that you could possibly fix if you weren’t too busy seeking attention.

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