The immune system is a chain/network of organs, antibodies, white blood cells, and chemicals. This system works to protect your body from harmful viruses, bacteria, and parasites that can cause infection or illness. The immune system works very hard to keep us healthy by either destroying the germs or by limiting the extent of how much they can harm us. It can find out, which cells are of our body and which cells are not. It can activate, mobilize, attack, and kill the foreign invading germ if any. 

The immune system finds out about the germs after when your body is exposed to the germs. The body can develop antibodies to the foreign cells (the germs) to keep the germs in check. If you take an example, when you take a vaccine, the immune system develops an antibody to the germ. It will destroy the germs if it comes in contact with the body in the future.

There are cases when the antibodies do not stop mounting attacks even after the germs are killed, this can cause autoimmune diseases and allergic reactions.

Parts of the Immune System

The immune system is made up of a network/chain of cells and organs. These cells/organs help us to get better when we are sick. The main parts of the immune system with the diagram are as follows:

1. White blood cells- The white blood cells act as protection against germs. It identifies the germs then attacks and destroys them to keep us safe and healthy. There are many types of white blood cells in our body, some of them are present in our bloodstream while some of them occupy certain tissues. Each of the cells has a specific way of doing its task, communicating with the other cells, and performing the needed actions. 
2. Bone marrow- The bone marrow makes new blood cells every day and releases them into the bloodstream so that they can fight against germs if any.
3. Thymus- This is a small organ in our upper chest beneath our breast bones, it helps in maturing a certain type of white blood cells. The specific task of these cells is to remember and recognize the invading germs, so that attack can be launched quickly the next time they try to invade.
4. Tonsils and adenoids- The tonsils and adenoids are located in your throat and nasal project so that they can trap foreign invaders as soon as they enter your body. They can produce antibodies that can protect us from any invaders from throat and lung infections. 
5. Spleen- Our spleen stores white blood cells which help in defending our body from foreign invaders. Its function is to filter blood, destroying old and damaged red blood cells.

Conditions and disorders that can affect the immune system  

There are many deficiencies and health conditions that can harm the immune system. Some medicines make it harder for the body to release antibodies and fight the infection. There are many health issues during which the immune system attacks healthy cells. The immune system is prone to many disorders, some of these conditions and disorders are as follows: 

1. Allergies- When our body overreacts to any substance (mostly harmless) the immune system gives a big counter towards that substance. Our body fights allergy triggers by releasing histamines that cause allergy symptoms. Allergic reactions can be mild as well severe which can even lead to death.
2. Cancer- There are certain cancer cells like leukemia, lymphoma, and myeloma which can affect the immune system directly. The cause of these cancers is when the immune cells multiply uncontrollably.
3. Infections- Infections like HIV and mononucleosis are well-known infections that can weaken the immune system and they can lead to serious illness.
4. Sepsis- It is a response to the substance by the immune system. It can trigger inflammation in the body and can cause a chain of events that can lead to death.
5. Medications- There are some medicines like corticosteroids that can weaken the immune system. 

Ways to keep your immune system healthy

Just like the other parts of the body, the immune system means that different parts of the immune system need rest and nourishment to stay fit. There are many changes that we can make in our lifestyle to stay healthy and avoid illness. Some of the ways to keep your immune system healthy are as follows:

1. We should exercise regularly. 
2. We should avoid regular intake of alcohol or consume it in moderation.
3. We should maintain a balanced diet
4. We should wash our hands often.
5. We should take sleeping time seriously. 

Conclusion 

The immune system is a chain/network of organs, antibodies, white blood cells, and chemicals. This system works to protect your body from harmful viruses, bacteria, and parasites that can cause infection or illness. The body can develop antibodies to the foreign cells (the germs) to keep the germs in check. If you take an example, when you take a vaccine, the immune system develops an antibody to the germ. It will destroy the germs if it comes in contact with the body in the future. 

The immune system is made up of a network/chain of cells and organs. These cells/organs help us to get better when we are sick. Some of the parts of the immune system are white blood cells, bone marrow, thymus, spleen and tonsils, and adenoids. 

Our immune system meaning different the immune system is prone to many disorders, some of them are allergies, cancer, infections, sepsis, and medications. Just like the other parts of the body, our immune system needs rest and nourishment to stay fit. Some of the ways to keep your immune system healthy are quitting smoking, washing hands often, maintaining a balanced diet, etc.