1. Chapter 40 Section 2
The Immune System

2. Agents of disease are called pathogens or antigens, Examples include:
Fungi
Protists
Worms
Cont.

3. Bacteria
CUTS AND PUNCTURES
OSE
and

4. Viruses
Swine Flu
Virus
Common Cold Virus
HIV Virus

5. Pathogens enter the body through various body openings
EYE
NOSE
MOUTH

6. and breaks in the skin

7. Disease can be transmitted to humans in various ways:
Airborne droplets or dust particles
Spoiled food
Common inanimate objects

8. And vectors Like insects.
For example:The parasite that causes malaria is transmitted by mosquitos.
The mosquito is the vector.

9. And of course…
Touching

10. Defenses against disease
Nonspecific defenses prevent pathogens from entering the body
Specific Defenses
the immune response, the body’s response to the presence of a disease causing antigen

11. Nonspecific Defenses
Your skin is your first and most important line of defense against disease
Body secretions (mucus, oils, sweat, tears, and saliva) provide protection from pathogens as well.

12. Nonspecific Defenses cont.
An Inflammatory Response is a response caused by injury to, or infection of the tissues.
- Redness, swelling, pain, and heat(fever) are all part of the immune response to rid your body of harmful agents.
- White blood cells (phagocytes) rush to the scene of the
injury to prevent the spread of the pathogen.

13. Nonspecific Defenses cont.
Pus is a collection of living and dead white blood cells, and pathogens.
The pus will continue to form until the infection has ended. Once over, the pus will be cleared away by macrophages (a type of white blood cell).

14. Nonspecific Defenses cont.
Fever – fever kills many pathogens and speeds up the action of white blood cells
Interferon - proteins which help resist viral infection

15. Specific Defenses
The immune response, is a series of specific defenses that attack antigens.
Antibodies are specifically made to recognize the antigen and attack/destroy it.

16. Specific Defenses cont.
2 types of Immune Responses
Cell Mediated – defense against abnormal cells and pathogens inside living cells
Hummoral Immunity – defense against pathogen in body fluids

17. Function
The function of the immune system is to fight infection through the production of cells that inactivate foreign substance or cells.
Defenses:
Nonspecific: skin, mucus, sweat, tears,
Inflammatory response,
Specific: Hummoral immunity and cell- mediated immunity, acquired immunity (Vaccines)

18. Organs of the Immune System

19. Homeostasis
The body must defend itself from pathogens and foreign materials to maintain homeostasis. The immune system is the body’s main defense against pathogens.
It recognizes, attacks, destroys and remembers each type that enters the body.

20. Immune System Disorders
Allergies
Allergies are an overreaction of the immune system.
Allergens cause immune cells to release histamines which trigger mucus production (sneezing, watery eyes, runny nose etc.) and increased fluid/blood flow.
Autoimmune disease
When the immune system makes a mistake and attacks the body’s own cells, it produces an autoimmune disease.

21. Lymphatic system
Chapter 37 Section 2

22. Lymphatic system function
Collects fluid that is lost by the blood and returns it back to the circulatory system.
As the fluid is transported, the lymph nodes filter/traps bacteria and other pathogens.
Microorganisms are destroyed in the nodes.
Old or damaged red blood cells are destroyed in the spleen.
Lymph fluid then is ready to be returned to the circulatory system.
Carries fat-soluble vitamins to the blood from the digestive system.

24. The lymphatic system organs
Lymph vessels: lymph travels through to return to the circulatory system
Lymph nodes: filters foreign particles out of the lymph
Thymus: gland that helps white blood cells mature
Spleen: destroys damaged red blood cells and platelets.

25. Homeostasis
The lymphatic system helps maintain homeostasis in several ways.
Returns lost fluid back to the circulatory system to avoid swelling
Filters and cleans lymph fluid from foreign pathogens, damaged cells etc.
Helps mature white blood cells which help fight infections.