Login

Autoimmune Diseases and Hypersensitivity

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Blood Types: ABO System, Red Blood Cell Antigens & Blood Groups

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

Take Quiz Watch Next Lesson
 Replay
Your next lesson will play in 10 seconds
  • 0:41 Autoimmune Disease
  • 2:08 Hypersensitivity Reactions
  • 3:35 Examples of Autoimmune Disease
  • 4:56 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
Create an account to start this course today
Try it free for 5 days!
Create An Account

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Artem Cheprasov
This lesson will talk about what defines an autoimmune disease, a hypersensitivity reaction, and more. We'll also discuss Graves' disease and myasthenia gravis.

Friendly Fire

When police officers or military personnel undergo training, they need to learn how to recognize the bad guy from the good guy. They need to quickly react. They need to accurately shoot the burglar but purposefully avoid shooting the person being burglarized. Sometimes, due to a bad judgment call or poor training, friendly fire does occur. The friendly fire ends up hurting the good guys. This same type of deal can occur in our body as well.

Autoimmune Disease

When our own body's white blood cells, called lymphocytes, undergo maturation and training, they learn to recognize what is considered to be a friend, like a cell that belongs to our body, and what is the bad guy, like a virus or bacteria. They do this by being exposed to antigens, the little particles of the cells I mentioned, which our immune system can recognize and respond to.

However, sometimes these training processes go haywire for more than one reason. These reasons and how they develop and progress are outside of the scope of this lesson. However, what you need to know is that sometimes an autoimmune disease, or an immune response specific to self-antigens, can occur.

Normally, the cops, our lymphocytes, train to purposefully ignore shooting the good guy, the self-antigen - meaning the police officers don't just not shoot the good guy because they were trained to only shoot the bad guy. No, they actively avoid shooting the good guy as much as they actively try and shoot the bad guy. Self-tolerance, the ability to not attack our own body's antigens, is an active physiological process.

Hypersensitivity Reactions

Therefore, any time that our body overreacts to a self-antigen and begins to produce antibodies directed against our own body's cells or receptors, called autoantibodies, or allows self-reactive lymphocytes called T cells to damage our body's cells, we call this autoimmunity.

Autoimmunity is just one cause of something known as a hypersensitivity reaction. A hypersensitivity reaction is a reaction in which our own body's immune cells overreact to an antigen and cause excessive inflammation and damage to our own body's cells and receptors in the process.

I don't want you to think, however, that all hypersensitivity reactions are autoimmune diseases. That's not true!

Autoimmune diseases have cops, the lymphocytes, that directly target the good guys and avoid the bad guys altogether. A hypersensitivity reaction can be either that or a process whereby a cop targets a bad guy but also hits a good guy by accident with the same shot - meaning the cop damages our own body's cells indirectly, or by extension, and in the process of trying to get the bad guy, like a virus or bacteria.

Examples of Autoimmune Disease

In any case, some famous examples of autoimmune diseases include myasthenia gravis and Graves' disease. In the former, antibodies target our own body's receptors at the neuromuscular junction and block certain chemicals from binding to and stimulating the receptors on the muscle cells that cause muscles to contract. This causes things like difficulty walking, eating, talking, and so on - basically anything that involves the use of your muscles.

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

Register for a free trial

Are you a student or a teacher?
I am 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

Earning College Credit

Did you know… We have over 95 college courses that prepare you to earn credit by exam that is accepted by over 2,000 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 free for 5 days!
Create An Account
Support