2. Nonspecific immune defenses The immune system protects your body from pathogens

3. Resistance Resistance is your bodies ability to defend against pathogens. Your immune system gives you resistance.

4. physical barriers to disease Nonspecific defense. – Sweat, oils, & waxes. – Mucous membranes. – HCL of stomach.

5. Why you get a fever Pathogens that attack human body like 98.6° F best. Raising temperature of body increases effectiveness of white blood cells. Decreases effectiveness of pathogen.

6. Interferon Chemical released by cells infected by viruses. Causes surrounding cells to resist infection.

7. Inflammatory Response Symptoms: –Redness –Heat –Swelling, pain What occurs: –Damaged cells release histamines. –Causes vasodialation –Causes increase in permeability. Inflammatory response occurs when pathogen penetrates the skin. Pair share: explain this picture to your partner. What is happening in each frame?

8. Neutrophils Most common white blood cell Kill pathogens using phagocytosis. Circulate in blood stream. Migrate towards site of infection. Move out of the blood stream

9. Macrophages Stationed in certain tissues. Destroy by phagocytosis. Rid the body of debris and damaged cells.

10. Natural Killer Cells Attack cells which have been infected by pathogen. Kills cancer cells. Kills by puncturing cell membrane.

11. summary 1.List 3 nonspecific defense barriers. 2.List 3 symptoms of the inflammatory response. 3.What do macrophages do?