1. How Do We Get Sick?
Almost everyone gets sick. Diseases are any changes, other than injuries, that disrupt the normal functions of the body.
Diseases can be inherited, caused by materials in the environment, or produced by disease-causing organisms. These organisms are called pathogens. Diseases caused by pathogens are generally infectious because the pathogens usually infect, or enter, the body of the person that gets sick.
1. On a sheet of paper, make a list of some of the infectious diseases you have had.
2. Choose one of the diseases on your list. How did you feel when you were sick with this disease? How was the disease treated?
3. How did you get the disease described in question 2? What do you think caused this disease?

2. Pathogens and Disease Review
Pathogen Types
Disease
Agent That Causes Disease
Method of Transmission
Common cold
Rhinovirus
Two types (A, B), plus subtypes
Varicella
Paramyxovirus
Mycobacterium tuberculosis
Neisseria meningitidis
Vibrio cholerae
Clostridium tetani
Trypanosoma
Plasmodium
Entamoeba histolytica
Schistosoma
Taenia saginata
Imperfect fungi
Airborne; direct contact with infected person
Airborne; droplet infection; direct contact with infected person
Droplets in air; direct contact with secretions of infected person
Droplets in air; contaminated milk and dairy products
Direct contact with a carrier
Contaminated drinking water
Contaminated wound; usually puncture wound
Spread by tsetse fly
Spread by Anopheles mosquitoes
Freshwater streams and rice paddies
Contaminated meat
Contact with infected person
Exchange of hats, combs, or athletic head gear with infected person
Viruses
Influenza
Chickenpox
Measles
Bacteria
Tuberculosis
Meningitis
Cholera
Tetanus
Protists
African sleeping sickness
Malaria
Amoebic dysentery
Worms
Schistosomiasis
Beef tapeworm
Fungi
Athlete’s foot
Ringworm

3. Do Now: 1. Turn in Lab report to bin
Do Now: 1. Turn in Lab report to bin. Make sure to have green rubric attached with your name on it List one illness you have had in the past year. - Describe the symptoms. - Describe the treatment. - Describe how this illness is transmitted Write down what how you think the immune system protects us from pathogens.

4. IMMUNITY Immunity: Pathogen:
ability of the body to resist a specific pathogen
Pathogen:
disease causing agent or organism

5. IMMUNITY
There are three “lines of defense” within your body that serve to keep you healthy………

6. Two types of defense mechanisms
Non-specific – prevent pathogens from entering the body
Specific – Destroy harmful pathogens that enter the body
Draw a picture of body with bacteria outside.
Draw a picture of body with bacteria inside.

7. “Keep pathogens out of the body tissues - Non-specific defense”
1st Line of Defense
“Keep pathogens out of the body tissues - Non-specific defense”
Skin (most important)
Tears
Hair
Mucus membranes
Saliva
Stomach acid
Earwax
Lysozyme: is an enzyme which breaks down the cell walls of bacteria; present in body secretions

8. Destroy them non-specifically with an inflammatory response”
2nd Line of Defense
“Pathogens have invaded body.
Destroy them non-specifically with an inflammatory response”
Example:
If pathogens enter the body, histamines are released which allow phagocytic (pathogen eating) white blood cells move into the area to destroy the bacteria
Histamine: chemical that tells white blood cells to move to area of infection
Symptoms
swelling, warmth
redness, pain
pus
Antihistamines: drugs that stop the histamine response
Allergic response is too much histamine being produced
Histamine increases the permeability of the capillaries to white blood cells and some proteins, to allow them to engage pathogens in the infected tissues.

9. The Inflammatory Response
Briefly describe the diagram below.
Wound
Skin
Phagocytes move into the area
Bacteria enter the wound
Capillary

10. So an increase in WBC’s means….

11. 2nd Line of Defense Continued…
A FEVER IS A GOOD THING……….
The immune system also releases a chemical that increases your body temperature which can kill the pathogens
The fever also increases heart rate so white blood cells can get to the infection site faster.
Discuss homeostasis, a fever is outside the optimal range for pathogens to comfortably live and multiply

12. 3rd Line of Defense - The Immune Response -
“The 2nd line of defense has failed. Resort to killing the pathogens specifically with chemical warfare.”
White blood cells release “antibodies” to attach to “antigens” on the pathogens and destroy them.
White blood (B-Cells) cells “remember” how to make those antibodies for the future.
antibody
What is the different between non-specific and specific – clarify during this slide

13. 3rd Line of Defense - The Immune Response -
“The 2nd line of defense has failed. Resort to killing the pathogens specifically with chemical warfare.”
White blood cells release “antibodies” to attach to “antigens” on the pathogens and destroy them.
White blood (B-Cells) cells “remember” how to make those antibodies for the future.
What is the different between non-specific and specific – clarify during this slide

14. Antigen- binding sites
How Does the White Blood Cell Know What to Attack? Each pathogen has a different shape antigen (surface protein) and only specific antibodies will bind with it and destroy the pathogen.
Antigen- binding sites
Antigen
Antibody
How can we compare antibodies and antigens to a lock and key model?

15. There are three “lines of defense” within your body that serve to keep you healthy………
1st Line of Defense
2nd Line of Defense
3rd Line of Defense

16. Why is it that people tend to get illnesses like Hand-Foot & Mouth Disease once, and then never again?
Primary immune response
Occurs when a specific pathogen
enters your body for the first time
It takes several days for WBC’s (T-cells) to
figure out how to make the
antibodies to destroy it
In the meantime, you get sick

17. Why is it that people tend to get illnesses like Hand-Foot & Mouth Disease once, and then never again?
Secondary Immune Response
Occurs when that same pathogen enters your body again
WBC’s, called Memory B-cells, remember that pathogen and how to make the antibody. They do so QUICKLY, before it has the chance to make you sick

18. What are Antibodies and Antigens
What are Antibodies and Antigens? What do they have to do with your immune response when your body is exposed to a familiar pathogen?

19. SLOW antibody production pathogen has opportunity to reproduce
YOU GET SICK
FAST antibody production
pathogen has no opportunity to reproduce
YOU DON’T GET SICK
Might not do active and passive immunity – only if you have time

20. Made possible by memory cells. -- permanent immunity --
Active Immunity
Occurs when your own white blood cells (B-cells) learn and remember how to make the necessary antibodies that kill a pathogen, keeping you immune for your whole life.
Made possible by memory cells.
-- permanent immunity --
Examples:
having hand, foot & mouth disease
once, then never again
immunity after a vaccination
a vaccine is a weakened form of a pathogen which causes your body to make antibodies to it

21. Passive Immunity -- temporary immunity --
Occurs when you receive the antibodies of immunity from somebody else
-- temporary immunity --
Examples:
being immune to a pathogen for a few months after receiving a blood transfusion
fetus developing inside its mother
baby for 6 months after birth
breastfeeding baby

22. Briefly describe the difference between active immunity and passive immunity?