1. 2 December 2013 Questions
Trivia: 60% of bosses don't believe you when you tell them this.
Trivia 2: 40% of dog owners admit to having done this, what is it?

2. Unit 8 "Communicable & Chronic Diseases"
Lesson 44 "Avoiding Communicable Diseases"

3. Objectives Students will be able to...
(1) Explain how the immune system responds when a pathogen enters the body.
(2) Discuss ways to develop active & passive immunity.
(3) Identify types of pathogens that cause disease, and give examples of the types of diseases caused by the types of pathogens.
(4) Discuss ways pathogens are spread.
(5) Analyze strategies to prevent infection with communicable diseases.

4. The Immune System
The system that removes harmful organisms from the blood and combats pathogens.
Composed of body organs, cells, & chemicals.
Tears, perspiration, saliva, & skin oils kill many pathogens.
Skin acts as a barrier to prevent pathogens from entering the body.
Pathogens that are swallowed are killed by stomach acids

5. Protection Inside the Body
Lymphocytes: White blood cells that help the body fight pathogens.
B Cell: A white blood cell that produces antibodies.
Antibody: A special protein that helps fight infection.
Helper T Cell: A white blood cell that signals B cells to produce antibodies
Macrophage: A white blood cell that surrounds & destroys pathogens.

6. How Does the Immune System Work?
8 steps:
(1) Pathogen enters the body
(2) Lymphocytes multiply in lymph tissue to fight pathogen.
(3) Helper T cells send signals to B cells to produce antibodies.
(4) B cells enter lymph nodes & other lymph tissues.
(5) Antibodies travel through blood to destroy the pathogen (antibodies make pathogens ineffective and sensitive to macrophages)
(6) Antibodies attach themselves to pathogens & weaken pathogen.
(7) Macrophages surround and kill pathogen.
(8) Destroyed pathogen is filtered through lymph nodes and removed by the spleen.

7. Immunity The body's resistance to disease-causing agents.
Active Immunity: Resistance to disease due to the presence of antibodies.
Example: After a person recovers from the chicken pox virus, the chicken pox antibody remains in the body & protects that person from developing chicken pox again.
Vaccine: A substance containing dead or weakened pathogens that is introduced into the body to give immunity.
2 Types: Live-Virus Vaccine; Killed-Virus Vaccine
Passive Immunity: Immunity that results from introducing antibodies into a person's blood stream.

8. Containing Pathogens Pathogen: A germ that causes disease.
Communicable Disease: An illness caused by pathogens that can be spread from one living thing to another.

9. Four Types of Pathogens
How Are Pathogens Spread?
Bacteria
Single-celled organisms.
Most are beneficial but some cause diseases
Examples: Strep throat, tetanus, Lyme Disease, diptheria
Fungi
Single or multi-celled parasitic organisms
Athlete's Foot, Ringworm, Jock Itch, nail infections
Viruses
One of the smallest known pathogens
Common Cold, mumps, hepatitis, mono, chicken pox, flu
Protozoa
Tiny, single-celled organisms that produce toxins that cause disease.
Malaria, African Sleeping Sickness, dysentary.