the Immune System

Unit 12: The Immune System “The war inside your body” Immunity VS disease

The Immune System Function: Recognizes foreign molecules and acts to immobilize, neutralize, or destroy them

Most of the time good prevails…

…Sometimes evil is too much!

What is the evil? Pathogens Harmful or disease causing organisms.

5 Types of Pathogens (Largest to Smallest) 1. Parasitic Worms 2. Fungi 3. Protozoa 4. Bacteria 5. Viruses

the Immune System

2 Types of Defenses Innate Defense and Adaptive Defense (“Non-Specific”) (“Specific”)

“Non-Specific” Defense Innate Immune system “Non-Specific” Defense When you were born you already had several mechanisms to prevent illness both Externally and Internally.

“Non-Specific” Defense Innate Immune system “Non-Specific” Defense External Defenses: 1st Line of Defense - Surface Barriers 1. Integumentary System: Skin is a natural barrier that repels pathogens

“Non-Specific” Defense Innate Immune system “Non-Specific” Defense External Defenses: 1st Line of Defense - Surface Barriers 2. Digestive System: High Acidity in stomach kills pathogens

“Non-Specific” Defense Innate Immune system “Non-Specific” Defense External Defenses: 1st Line of Defense - Surface Barriers 3. Respiratory System: Mucus traps pathogens I’m sorry your SNOT feeling well!

“Non-Specific” Defense Innate Immune system “Non-Specific” Defense Internal Defenses: 2nd Line of Defense Phagocytes: Engulfs/Destroys Pathogen at site of infection Macrophages: “Big Eaters” engulfs cellular debris, foreign substances, bacteria, and cancer cells Neutrophils: Most abundant, engulfs bacteria, they die in the process too

“Non-Specific” Defense Innate Immune system “Non-Specific” Defense Internal Defenses: 2nd Line of Defense Basophils: Releases Histamine in response to allergic reaction

“Non-Specific” Defense Innate Immune system “Non-Specific” Defense Internal Defenses: 2nd Line of Defense Natural Killer (NK) Cells: Actively scan the body for cells for “Self Antigens” (ID Badge). No ID badge? Cell is attacked! This is the body’s first line of defense vs Cancer.

“Non-Specific” Defense Innate Immune system “Non-Specific” Defense Internal Defenses: 2nd Line of Defense Inflammation Response: A series of “Non-Specific” events that occur in response to pathogens. The response typically produces redness, swelling, heat, and pain in the target area. When a pathogen enter the body, the following events occur: Vasodilation: Redness and Heat “Hyperemia” Vascular Permeability: Swelling Phagocytes Arrive: Engulf pathogens

“Non-Specific” Defense Innate Immune system “Non-Specific” Defense Internal Defenses: 2nd Line of Defense Fever Response When Pathogens invade, the body produces “Pyrogens”, chemicals that force the Hypothalamus (regulates body temperature) to raise body temp. Increased body temp creates a hostile environment for pathogen to live in.

https://www.youtube.com/watch?v=nOO0x4J4hMQ

https://www.youtube.com/watch?v=Ky-gNIlejwM&noredirect=1 http://www.youtube.com/watch?v=CeVtPDjJBPU

Anatomy Test 12