Unit 1 Cells and Systems

Chapter The ummune system protects the human body.

3.1 The Acquired Immune Response

The immune response is how your body recognizes and defends itself against bacteria, viruses, and substances that appear foreign and harmful to the body.The immune system protects the body from potentially harmful substances by recognizing and responding to antigens. Antigens are molecules on the surface of cells, viruses, fungi, or bacteria. Non-living substances such as toxins, chemicals, drugs, and foreign particles such as a splinter can be antigens. The immune system recognizes and destroys substances that contain these antigens. Even your own body cells have proteins that are antigens. These include a group of antigens called HLA antigens. Your immune system learns to see these antigens as normal and does not usually react against them.


What are infectious diseases caused by?
They are caused by viruses and bacteria

What does the immune system do?
The immune system protects your body against viruses bacterial infections

What does the acquired immune response attack on?
Particular pathogen

What is a antigen?
a antigen is any substance the body cannot recognize from a virus to a splinter