Why Does the Body Attack Itself?

Lesson Plan - Get It!

Audio:

The immune system keeps you healthy by identifying and destroying pathogen invaders.

You learned how the body responds through three lines of defense and how we helped the body avoid disease in the first Related Lessons of our Immune System series, found in the right-hand sidebar.

Remember that the immune response begins with physical barriers like skin, chemical compounds, and hair. If invaders pass this barrier, they meet the inflammatory response, where tissues move resources like fluid and white blood cells to remove invaders.

Finally, the immune response uses specific cells to attack and destroy invading pathogens.

• The immune response protects our bodies, but what happens when the body cannot recognize an invader from a body cell?

A critical component of a healthy immune system is the ability to identify foreign cells and particles. When the body cannot differentiate between foreign and body cells, an individual can develop an autoimmune disease.

There are several autoimmune diseases, many of which have similar symptoms. They are all characterized by using immune cells to attack body tissues as foreign invaders.

• Have you noticed the phrase gluten-free on grocery store foods?

Celiac disease is an autoimmune disease where the body attacks the digestive tract in the presence of gluten. Gluten is a protein found in many foods: breads, tortillas, flavorings, soups, soy sauce, etc.

When an individual with Celiac disease eats gluten, the body starts to attack the small intestine, where nutrients are absorbed into the body.

The immune response destroys the special cells that remove nutrients from food. These cells extend into the cavity of the digestive system and look like tiny hairs working to collect nutrients from the food materials passing through.

When these cells are damaged, it causes extreme weight loss, hair loss, fatigue, and digestive issues.

Autoimmune diseases cause daily irritation and long-term complications. The immune system keeps you healthy and functioning, but it can also use your cells against you in autoimmune diseases.

Patients with an autoimmune disease cannot distinguish foreign invaders from body cells, which leads to symptoms and the need for treatment.

• How does the immune system respond to a pathogen in a normal immune response?
• How might this response damage tissues in an autoimmune disease?

Head to the Got It? section to watch a video about specific autoimmune responses.