• Home
  • Blogs
  • How Does Your Immune System Work?
Immunity For Grown-Ups

How Does Your Immune System Work?

01th August 2022

How Does Your Immune System Work?

Now that you've landed on this page, the first thing I would ask you to do is rewind your time two years back when the COVID-19 pandemic took the world by storm.

Probably one of the most challenging hardships faced by all of us, those two years taught us a lot, right from the importance of family and friends to recognizing our responsibilities as civilians.

But one of the hardest lessons we learned from the pandemic was the value of our HEALTH AND NUTRITION. We are now concerned and aware more than ever about our eating habits, exercise routines, and mental health.

When it comes to keeping ourselves healthy and fit, what is the one thing that's supposed to be at its most prominent best in our body?

IMMUNITY. It is one of the key markers of our health. Why? Here's the reason.

Every day, we are surrounded by microscopic organisms, many of which have the potential to harm our health.

Every object you touch, right from your door handle to that auto you took on the way to even groceries, might be covered in microscopic organisms.

That's where your immune system comes into play. It is the first line of defense in our body and particularly protects us against infections and harmful foreign agents.

But this is not all. There is much more to our immune system and the powers it holds when it comes to protecting our health.

Here is a guide to brief you on how your immune system works and why you need to have strong immunity.

What is the Immune System?

Your immune system is a complex network of different cells, organs, tissues, and proteins that collectively work together to fight off infections from foreign pathogens and various harmful microorganisms present around us all the time.

The immune system consists of a range of components, including:

White Blood Cells

These are made in the bone marrow and are a key part of our immune system. WBCs mainly identify foreign invaders like harmful bacteria, parasites, fungi, etc., and attack them. B-cells, T-cells, and natural killer cells are some of the immune cells which collectively comprise the WBCs.

Bone marrow

The spongy material found inside your bones is called bone marrow. It creates the white blood cells that fight infection, the platelets that aid in blood clotting, and the red blood cells that deliver oxygen throughout our bodies.


The body uses antibodies to fight off microorganisms and the toxins (poisons) they release with the help of antigens. Many different kinds of cells, molecules, proteins, and other molecules are involved in this process.

Lymphatic system

The lymphatic system is a complex network of tubes that deal with the body’s fluid levels and controls the invasion of harmful microorganisms that can cause infections and diseases.


The spleen is an organ that filters blood and eliminates microorganisms and destroys old or damaged red blood cells. Additionally, it creates immune system components that combat disease (including antibodies and lymphocytes).


The thymus produces T-lymphocytes, one of the most important immune cells of WBCs. Additionally, it also helps in blood filtration.

Three Lines of Defence Mechanisms in the Immune System

The immune system involves three lines of defense mechanisms against foreign invaders-

Physical and Chemical Barriers

Physical barriers are everything that helps in the eradication of pathogens from the surface level. These include skin, mucous membranes, hair, urine, saliva, tears, stools, etc.

Chemical barriers involve different kinds of enzymes produced by the body or the processes involving them and help in preventing the entry of foreign invaders into our system. Some common chemical barriers include gastric juice, lysozymes, sebum, acidity, etc.

Innate Immunity ( Non-Specific Response)

So, pathogens that pass the physical barriers then have to face the second line of defense. It plays a key role in building your immune system and fighting off infections by foreign invaders.

Made up of a collection of organs, tissues, and different cells, this line of defense suffices to stop the infection, or at least does not spread it further. It uses immune cells and proteins (neutrophils, macrophages, etc.) to produce an innate response to fight foreign pathogens.

However, there are specific circumstances that the innate immune system cannot handle, and that's where the immune system's adaptive reaction will then get to work.

Adaptive Immunity (Specific Response)

The third line of defense mainly works by eradicating pathogens that the immune system has already fought off.

So, by the time the body reaches its third line of defense, it already knows what to attack and fight against.

This specific response mechanism depends upon B-cells and T-cells which are responsible for antibody-mediated and cell-mediated immune responses, respectively.


Maintaining a healthy immune system is a very complex process for your biological system, but you can make it simpler by adopting healthy lifestyle choices and taking necessary precautions.

That being said, next time you enter your home or go out to run errands, do not forget to take extra care!

Back to blog