The Immune System

Keywords

Immune system, immunity, vaccine, red blood cells, white blood cells, phagocyte, lymphocyte, pathogen, antibody, antigen, microorganisms.

Introduction

You get ill, and you need to recuperate in order to feel better. But how does your body help you with this?

We have an immune system that helps fight infection. They identify pathogens that enter the body, and create antibodies that will attack and destroy those pathogens.

How it Works

On a cellular level, we have cells in our bloodstream that help protect us. These are called white blood cells. There are several different types, but for this purpose we are focusing on two :

Phagocyte: this will try and destroy all unknown pathogens in our body that are causing infection.

Lymphocyte: this creates specific antibodies to fight off infection.

Interesting fact: the phagocyte is like the Pac Man of the immune system. It literally engulfs pathogens and consumes them until they are gone.

How a Vaccine Works

A vaccine is an injection or imprint of a dead culture that we take to prevent us getting a disease or illness. To make this a bit simpler, they take some of the virus or infection that has already died, and deconstruct the DNA from it, and then try and make something that will react to it to destroy it.

What does an Antibody do?

A pathogenA microorganism that causes a disease. has antigens on it, so when it enters our system, the lymphocyte with the right type of antibody finds them, releases the antibody from the lymphocyte and attaches them to the antigens on the pathogen.

As a result of this, the antibody destroys the pathogen. How?

There are several ways an antibody works:

• Enzyme breakdown: using enzymesA biological catalyst that speed up chemical reactions., the antibody breaks open the cell membrane of the pathogen and splits it apart.
• Easier to breakup: making it easier to break down, the antibody helps phagocytes to break down the pathogen and work together.
• Sticking together: making the pathogen stick together makes it easier for the pathogen to be broken down by phagocytes.

Lymphocyte - A Closer Look

There are about 30% of our white blood cells that are lymphocytes, and of these, no two are the same. Why? Because they are each fitted with different antibodies. When we have a foreign body enter our system, each lymphocyte goes into action to find the right antibody for the antigen on the pathogen. Kind of like a Cinderella story where the prince is looking for the right person in the missing shoe.

Phagocyte - A Closer Look

The Phagocyte. The shovel of the white blood cell. The mop. It will eat up anything in its path (hence me referencing Pac Man previously), and will do this all day long to clear up the pathogen.

What it doesn't do is create any antibodies. So in effect, when a pathogen first enters our body, the phagocyte will still work against it, consuming whatever pathogen is there, but it might not actually have much effect until the right lymphocyte has worked on it.