How the Human Immune System Works

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: What Are Viruses? - Definition, Structure & Function

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
 Replay
Your next lesson will play in 10 seconds
  • 0:02 immune System
  • 0:41 Phagocytes
  • 1:18 Lymphocytes
  • 3:00 Immunizations
  • 4:04 Lesson Summary
Add to Add to Add to

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Login or Sign up

Timeline
Autoplay
Autoplay
Lesson Transcript
Instructor: Rebecca Gillaspy

Dr. Gillaspy has taught health science at University of Phoenix and Ashford University and has a degree from Palmer College of Chiropractic.

Your immune system protects you against microorganisms that could make you sick. It is made up of an army of white blood cells that work together to recognize and destroy the bad guys. Learn how your immune system and immunizations work.

Immune System

The United States of America has a military force that protects our homeland from invaders. Your body has a similar force called your immune system, which is a collection of tissues and cells that protect against germs and other invading microorganisms. When the bad guys like bacteria, viruses, microbes, toxins and parasites try to get in, your immune system deploys its huge army of soldiers, or defending cells to keep you safe from infection and disease known as your white blood cells. Let's take a look at these soldiers and how they work together to defend your body.

Phagocytes

I mentioned that your immune system is made up of a huge army, and I was not kidding. Your body makes millions of white blood cells every day in places like your bone marrow, which is the soft tissue inside your bones.

You have different types of white blood cells. Some called phagocytes are cells that eat up and destroy other cells. In fact, the prefix 'phago' means 'eating', and the suffix 'cytes' means 'cells'; so, these guys are literally eating cells, and if you are a bacteria or other invader, you do not want to be found by these guys, because you will be eaten alive.

Lymphocytes

Phagocytes are always on patrol going out on seek-and-destroy missions aimed at foreign invaders. These guys aren't really specific, and their orders are to shoot first and ask questions later. This makes them different from another type of white blood cell called lymphocytes. Lymphocytes are white blood cells that recognize and deactivate specific foreign substances. Whereas phagocytes go out and kill anything they don't recognize, lymphocytes are more like trained assassins. They learn about the bad guys the first time they see them and then remember them if they ever try to invade again.

Here's how lymphocytes work. Sometimes your body is invaded by a bacteria, virus, or other foreign substance that induces an immune response. We call this an antigen. It's detected, and your immune system is called into action. One of the first things to happen is specific lymphocytes called B lymphocytes, or simply B Cells, make antibodies. You want antibodies to form because they are specialized protein molecules that are designed to lock onto and disable specific antigens. Antibodies are good at their job and handily apprehended the bad guys (a.k.a. antigens). But destruction of the antigens requires a different type of white blood cell, which we call T lymphocytes, or T Cells. There are different subsets of T cells, but some known as the killer T cells destroy the antigens that have been marked by the antibodies.

To unlock this lesson you must be a Study.com Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use Study.com

Become a Study.com member and start learning now.
Become a Member  Back
What teachers are saying about Study.com
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 160 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? Study.com has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create An Account
Support