TOPIC: Immunity AIM: How does the immune system protect the body against disease?

What are Antigens and Antibodies?

The Body’s Lines of Defense

1st line Physical barriers  keep pathogens out of the body: They are nonspecific: try to keep all out

skin, mucus, cilia, sweat, tears, saliva, digestive enzymes

2nd line 1. Inflammatory response: WBC’s destroy pathogens

WBC’s produce Antibodies that will attach to Antigens on the Pathogen. (3rd line) WBC’s produce Antibodies that will attach to Antigens on the Pathogen.

How do Antibodies work? They have a specific shape and attach to a specific FOREIGN ANTIGEN on the Pathogen. (They act like handcuffs and mark the pathogen to be destroyed) How does a marked Pathogen get destroyed? Macrophages : Engulf the entire clump (phagocytosis)

Foreign Proteins found on the Pathogen. Trigger the Immune Response and Antibody production. Antigen

How are antibodies made? 2 types of WBC’s T cells tell B cells to make antibodies

AIDS Acquired Immune Deficiency Syndrome Infectious disease

Caused by HIV (Human immunodeficiency virus)

Damages immune system by destroying T cells (body can’t fight off pathogens)

1. Contact with infected blood 2. Sharing intravenous needles How is HIV transmitted? 1. Contact with infected blood 2. Sharing intravenous needles 3. Sexual contact 4. Motherfetus

An immune response or reaction to substances you are allergic (sensitive) to Allergies

Allergen = what you are allergic to (pollen, dust, etc)

Histamines produced (chemicals released by cells that cause symptoms)

Review: What is a pathogen? Explain what makes up your body’s first line of defense. How are antibodies produced? How are infectious diseases different from noninfectious diseases? How does HIV affect the body? What is an allergy?