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The Immune System in Kids

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Last updated date: 17th Jul 2024
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What is the Immune System?

The immune system is the capability of the body to protect us from foreign antigens. The vast and complex network of proteins, cells, and organs protects our body from external infections caused by bacteria, viruses, fungi, etc. Our body has three types of immunity: innate, adaptive and passive. Some organs act like shields against germs, preventing germs from entering our bodies. Let us read ahead to learn more about the immune system for kids and how it functions.

Immune System

Like the other systems of our body, such as the respiratory, circulatory, and digestive systems, we have an immune system that provides us with immunity. It is a large network of organs like red blood cells, white blood cells, lymphocytes, spleen, bone marrow, thymus, and the lymphatic system that guard against infections and diseases.

The immune system protects us from unwanted germs in our body whenever we become sick. Fever is a slight rise in the body's temperature and is one of the most common symptoms of any disease. The body temperature increases due to the immune action of our immune system. Whenever we get a fever, it means that the immune system is working against the virus.

Organs Involved in the Immune System

Our immune system comprises various fighter cells and is a very important organ of immunity. These are as follows:

  • Thymus- Thymus is located in our neck and is home to the fighter cells.

  • Bone Marrow- The bone marrow is the mother of all cells in our blood.

  • Spleen- The spleen is present just below the stomach on the left side.

  • Lymph Nodes- The lymph nodes are present throughout the body, mainly on the neck, under arms and abdomen.

  • Tonsils–  They act like a gate for germs to enter our bodies.

Immune System

Immune System

Types of Cells Producing Immune Response

1. B-cells

2. T-cells

Both cells are formed in bone marrow, but T-cells travel to the thymus and live there. T-cells and B-cells are also known as fighter cells. Many other cells, like neutrophils, monocytes, etc., are collectively called leukocytes or white blood cells (WBCs). WBCs are thus called immune cells.

Types of Immunity

Immunity is of two types, active immunity and passive immunity.

  • Active Immunity – Active immunity is the type of immunity we gain from exposure to germs over a long period. We can say that we do not acquire this immunity from someone else but generate it ourselves due to exposure to pathogens.

  • Passive Immunity – Passive immunity has been present in our body since birth. This means that the baby acquires this immunity from the mother.

We mainly rely on active immunity rather than passive immunity. We have acquired this immunity through exposure to germs in the air, the food we eat, touch, etc. This immunity lasts for a long time in the form of memory. B cells and T cells help in memory generation.


Immunisation imparts artificially induced immunity in our bodies. During immunisation, there are types of vaccines that are injected into our bodies which carry pathogens. As these pathogens are inactive or dead microbes, they act as a teacher in our body who teach our immune system to produce antigens in our body to fight particular types of disease. Immunisation starts right from birth. Some vaccines help fight against diseases like flu, rubella, polio, chickenpox, mumps, covid 19, etc.



Solved Questions

1. How are T-cells generated?

T-cells are generated in the bone marrow.

2. What is the first line of defence?

The first line of defence is innate immunity


The immune system helps to protect our body from various diseases. It fights the disease-causing organism and eliminates them from our bodies. The immune system is very important for the human body because, without immunity, we become ill very frequently. Hence, various organs are involved in the immune system, such as bone marrow, spleen, lymph nodes, timers etc. Immunity can be boosted with the help of vaccines. Immunity is of two types active immunity and passive immunity.

FAQs on The Immune System in Kids

1. What are cellular barriers in our body?

Cellular barriers in the human body are neutrophils, lymphocytes and monocytes.

2. What is inflammation?

Inflammation is the immune system's response to any injury or external germs in our body.

3. What is an epidemic disease?

Epidemic disease is a disease which spreads to a large number of people at the same time. For example, Swine Flu was an epidemic disease.

4. What is immunology?

It is the branch of Biology which studies the immune system.

5. Does saliva act as a barrier to germs?

Yes, Saliva is a digestive enzyme present in our mouth; its main function is to help in breaking down the food we eat into smaller components and also help in swallowing, but it also plays a role in acting as a barrier to germs because it traps the germs in the mouth itself. Some components of saliva also have bactericidal activity.