1. Immune & Lymphatic System
How Does the Human Body Respond to Sickness?

2. Disease
Any changes, other than injuries, that disrupt the normal functions of the body
Can be caused by inherited DNA, materials in the environment, or disease-causing agents (pathogens)
Diseases caused by pathogens - infectious diseases

3. Pathogens Viruses – influenza, smallpox, warts
Bacteria – strep, anthrax, botulism
Protists – malaria, amebic dysentery
Fungi – athlete’s foot, ringworm
Worms – tapeworm, hookworm

4. Spread of Disease Physical contact – air, blood, body fluids
Contaminated food & water – food poisoning, uncooked meat
Infected animals (vectors) - ticks, mosquitos, fleas, mammals

5. Fighting Disease Antibiotics Antiviral drugs
Healthy lifestyle – including rest, well-balanced diet, exercise, regular Dr. checkups, avoid harmful activities (alcohol, tobacco, drugs)

6. How do we defend against these invaders?
Immune System
Function: to fight infection by producing cells that destroy foreign substances

7. Acquired Immunity Prevents a Person from Getting Sick

8. Acquired Immunity Active – natural exposure or vaccine
Passive – antibodies transferred from mother to baby

9. The immune system has many responses to pathogens and foreign cells

10. Nonspecific Defenses
1st line – skin (most impt), secretions (mucus, tears, saliva, sweat)
2nd line – inflammatory response
swelling, pain, fever

11. Inflammatory Response
Skin
Wound
Bacteria enter the wound
Phagocytes move into the area and engulf the bacteria and cell debris
Capillary

12. From time to time, foreign invaders slip past the body’s 1st & 2nd lines of defense and initiates an immune response

13. Cells & Proteins Fight the Body’s Infections
White Blood Cells: Phagocytes
Destroy pathogens by surrounding and engulfing them

14. Cells & Proteins Fight the Body’s Infections
White Blood Cells: Helper-T Cells
Destroy body cells that are infected with pathogens

15. Cells & Proteins Fight the Body’s Infections
White Blood Cells: B Cells
Produce proteins (antibodies) that inactivate pathogens that have not yet infected a body cell

16. Cells & Proteins Fight the Body’s Infections
White Blood Cells: B Cells
Bacterial
Cell

17. Cells & Proteins Fight the Body’s Infections
White Blood Cells: Memory Cells
Specialized cells that “remember” a pathogen that previously invaded the body

18. Think-Pair-Share
Using your knowledge of B cells and memory cells, describe how vaccines work.

19. Immune System Disorders
Allergies – Oversensitivity to a normally harmless agent.
Autoimmune diseases – immune system attacks healthy cells by mistake Type 1 diabetes, arthritis, multiple sclerosis

21. Immune System Disorders
AIDS - HIV attacks helper T cells

22. Think-Pair-Share
AIDS stands for Acquired Immunodeficiency Syndrome. Given that the HIV virus invades helper T cells, explain why AIDS is an appropriate name.

23. Lymphatic System
Works with circulatory & immune system to remove fluid from tissues
Lymph – fluid that leaves blood vessels & moves into tissues causing swelling
Lymph nodes – trap microbes, can swell → sign of illness

24. Importance of lymphatic system