Antibodies play a key role in the immune system.
They begin the process of getting rid of the invaders that may cause harm or infection. This lesson covers how antibodies work and the different kinds of antibodies.
What Are Antibodies?
Antibodies, also known as immunoglobulins, are Y-shaped proteins that are produced by the immune system to help stop intruders from harming the body.
When an intruder enters the body, the immune system springs into action. These invaders, which are called antigens, can be viruses, bacteria, or other chemicals. When an antigen is found in the body, the immune system will create antibodies to mark the antigen for the body to destroy.
The antibodies act sort of like the immune system’s scouts. They find antigens, stick to them, and identify for the immune system the exact type of antigen so that it can be destroyed. Each antibody is made for one and only one antigen, and it’s fitted with special receptors that will only bind to that antigen. For instance, a specific antibody is created to help destroy the chickenpox virus.
Only that particular antibody will attack a chickenpox virus.
How Antibodies Fight Antigens
So what happens when an antigen tries to enter the body? When it does, the immune system is triggered. Chemical signals are sent to alert all the different parts of the immune system into action.First, the virus is met by a type of cell called B cells. The B cells are responsible for creating antibodies to match the antigen. Remember, each type of antibody matches to only one antigen. After the B cells have created their antibodies, the antibodies stick to the virus, marking it for the next round of attack.
T cells are then ordered to attack the antigen that the antibodies have marked for it.After the antigen has been destroyed, the cleanup crew comes along. A wave of phagocytes, large cells that can consume foreign matter, eats the remains of the infection.
After an infection is defeated, the antibodies still remain in the body. They are left there to wait in case that particular antigen returns.
For example, after a person gets chickenpox, the antibody that was created by the immune system to get rid of the chickenpox will remain in the body. The next time the chickenpox virus tries to invade the patient, the antibody will be ready. It will instantly attach to the virus, calling the T cells and phagocytes much quicker, and stopping the infection much earlier.Immunizations take advantage of the fact that antibodies remain in the body after an infection is eradicated. Most immunizations consist of a weak or diluted form of an antigen – not enough of the antigen to make the patient sick, but just enough to trigger the creation of antibodies. This way, the body can instantly attack any form of the infection it encounters, stopping the infections before they begin.
Types Of Antibodies
In total, there are five types of antibodies. Each type is found in a different part of the body and has a different set of duties. Each one of them is referred to by a letter following the abbreviation Ig for immunoglobulin.The most common antibody we have is the IgG antibody. IgG is found in all of the body’s fluids. It makes up about 75-80% of all of our antibodies. These antibodies help to fight off bacteria and viruses.
To go with the flow of the fluids, IgG antibodies are the smallest antibodies in size.The biggest in size are the IgM group, found in the lymphatic and circulatory systems. The IgMs are the first responders, the first type of antibodies to confront invaders to these two systems.IgA antibodies are found around the body where the outside meets the inside, such as the eyes, ears, and nose. The digestive tract is exposed to outside objects such as food, so it too has IgA antibodies.
So do the fluids on the outside of the body, such as blood, sweat, and tears. IgAs protect us from the invaders that are trying to get in through these openings. They make up about 10-15% of the antibodies in our body.
IgE antibodies should be familiar to people with allergies. These guys are found in the lungs, skin, and mucous membranes, which encounter foreign substances like food, air, and surfaces. IgE antibodies are made to protect the body from antigens in those substances like pollen or certain foodborne chemicals. People with allergies make too many IgE antibodies. When these antibodies react to allergens, allergy-sufferers will feel the effects.IgD antibodies are a mystery; there’s not much we know about them other than that they are found in the chest and belly.
Antibodies are Y-shaped proteins that latch onto antigens, invaders looking to cause harm or infection to the body.
The antibodies work with the immune system to destroy these antigens. For every kind of antigen, there is a different type of antibody. Once the antigen is destroyed, the antibodies continue to hang around just in case the antigens decide to try and make a comeback.In total, there are five types of antibodies all over the body.
- IgG, found in all of the bodies fluids
- IgM, found in the lymphatic and circulatory systems
- IgA, found around the body where the outside meets the inside
- IgE, found in the lungs, skin, and mucous membranes
- IgD, found in the chest and belly
Definitions to Know
- Antibodies: immune system proteins that protect the body from invaders
- Antigens: the invaders; allergens, viruses, chemicals, etc.
- B cells: cells responsible for creating antibodies
- T cells: cells that attack the antigens
- Phagocytes: cells that consume foreign matter; the cleanup crew after the antigens have been destroyed
- Immunizations: weak form of the antigen given to patients so their immune systems will create the antibodies for it
Completing this lesson should teach you to:
- Define antibodies and antigens
- Explain how antibodies fight antigens, including the different types of cells
- Detail how immunizations work
- Identify the different types of antibodies