Physiology: The Immune System Rahul V Sara S Joe A Jasper C

Disease  A disease is any change, other than an injury, that disrupts the normal functions of the body.  A pathogen is a disease causing agent.  The agents of disease include: Viruses, Bacteria, Protists, Worms, and Fungi.

How are diseases spread?  Physical contact  Contaminated food and water  Infected animals

Koch’s Postulates  The pathogen should always be found in the body of a sick organism and should not be found in a healthy one  The pathogen must be isolated and grown in the laboratory in pure culture.  When the cultured pathogens are placed in a new host, they should cause the same disease that infected the original host.  The injected pathogen should be isolated from the second host. It should be identical to the original pathogen.

Non-specific Immune Response  Lines of defense  First Line of Defense  The skin and mucus prevents entry into the body  Second Line of Defense  Inflammatory Response, White Blood Cells, and Anti-microbial proteins.

Specific Immune Response  Pathogen  Macrophage  T Cell  B Cell  Antibodies  Macrophages engulf the pathogen.  The Macrophages bring the pathogen to the T Cells in order to tell the B Cells to start producing antibodies.  The antibodies then neutralize the pathogens.

Immunity  The ability to fight infections by producing cells that inactivate foreign substances.  Active Immunity  The body’s reaction to a vaccine.  Passive Immunity  Antibodies produced by other organisms are injected into another organism.  A vaccination is an injection of a weakened or mild form of a pathogen to produce immunity.

Allergies  Allergies  An overreaction by the Immune System to a harmless substance. Some allergens include pollen, dust, mold, etc.  One dangerous allergic reaction is Asthma. Asthma causes your air passageways to become more narrow, making it hard to breath.

Immune System Diseases  Autoimmune disease is a disease that causes the body to attack itself, because your immune system cannot differentiate your cells and the invading pathogen.  AIDS is and Immunodeficiency Disease, meaning that it attacks your immune system, making it hard to defend against disease. AIDS slowly destroys the number of Help T-Cells

Maintaining your Health  In order to stay healthy you should eat healthy, exercise, rest, and stay away from harmful activities.  A risk factor is anything that will increases the probability of getting a disease.  Some risk factors include the quality of air and water in your community. If your water quality and air quality is bad, then it is not a healthy environment.

Cancer  Cancer is a disease where your cells multiply without stopping and destroy healthy tissue.  Cancer cells form when something goes wrong with the enzyme that controls cells growth and reproduction.  Cancer cells will continue to grow and form a tumor, the mass of growing tissue.

Multiple Choice 1. A change that affects the normal functions of a person’s body is a a. disease b. pathogen c. toxin d. vector

2. Viruses, bacteria, and fungi are known as a. antibodies b. antigens c. pathogens d. toxins

3. Which are not one of Koch’s postulates? a. The pathogen must be isolated and grown in the laboratory in pure culture. b. The pathogen is found in the body of a sick organism and not a healthy one. c. If placed in a new host, the cultured pathogens should not cause the same disease. d. The injected pathogen should be isolated from the second host. It should be identical to the original pathogen.

4. The body’s most important nonspecific defense is a. saliva b. mucus c. tears d. skin

5. What provides immunity against antigens and pathogens in the body fluids? a. T-cells b. B-cells c. Antibodies d. Interferons

6. A substance that triggers an immune response? a. T-cells b. B-cells c. Antigens d. Interferons

7. What is a vector? a. Injection of a weakened or mild form of a pathogen to produce immunity. b. Proteins that recognize and bind to antigens c. Animals that carry pathogens from person to person d. A substance that triggers the immune response

8. What happens when the immune system makes a mistake and attacks the body’s own cells? a. It produces autoimmune diseases. b. It produces pathogens. c. It produces an inflammatory response. d. None of the above.

9. Which are of the following are risk factors? a. Bad air quality. b. Exposure to solar radiation. c. Poisonous wastes in landfills. d. All of the above.

10. Which of the following are important factors in maintaining one’s health? a. Staying updated on current events. b. A healthful diet C. Abstaining from harmful activities d. b and c

Answers 1. A 2. C 3. C 4. D 5. B 6. C 7. C 8. A 9. D 10. D