First Two Lines of Defense

Day 2

First Two Lines of Defense

 

Lesson Objectives

• Describe you body's first line of defense against pathogens.
• Explain how inflammation helps protect you from pathogens.

Your body has many ways to protect you from pathogens. Like a castle, you body has a series of defenses. Only pathogens that get through all the defenses can harm you.

Your first line of defense is like a castle's moat and walls. It keeps most pathogens out of you body.

 The skin is the body's largest organ. The skin is also the body's most important defense against disease. The skin has many layers. The outer layer is tough and waterproof.

Most body fluids that you release from you body, contain chemicals that kill pathogens. For example, mucus, sweat, tears, and salvia contain enzymes that kill pathogens. The enzymes are called lysozymes. They break down the cell walls of bacteria to kill.

The stomach also releases a very strong acid, called hydrochloric acid. This acid kills most pathogens that enter the stomach in food and water. Urine is also acidic, so few pathogens can grow in it.