1. Ch 18 Fighting Diseases

2. Infectious Disease Understanding Infections Disease
Organisms that cause disease are called pathogens
Diseases that are caused by pathogens are called infectious disease which is a disease that is caused by the presence of a living thing within the body
When you have an infectious disease, pathogens have gotten inside your body and caused harm
Pathogens make you sick by damaging individual cells, even though you may feel pain throughout your body

3. Infectious Disease Kinds of Pathogens Bacteria Viruses Fungi Protists
Toxin: other bacterial pathogens damage cells indiretly by producing this
Viruses
Fungi
Protists

4. Infectious Disease How Pathogens Are Spread
Pathogens can spread though contact with either an infected person; soil, food, or water; a contaminated object; or an infected animal
Infected People
Soil, Food, and Water
Contaminated Objects

5. The Body’s Defenses Barriers That Keep Pathogens Out
There are 3 lines of defense against pathogens
In the first line of defense, the surfaces of the skin, breathing passages, mouth, and stomach function as barriers to pathogens. These barriers trap and kill most pathogens with which you come into contact
Skin
Breathing Passages
Mouth and Stomach

6. The Body’s Defenses The Inflammatory Response
When body cells are damaged, they release chemicals that trigger the inflammatory response, which is the body’s second line of defense
In the inflammatory response, fluid and white blood cells leak from blood vessels into nearby tissues. The white blood cells then fight the pathogens
Which Blood Cells
Phagocyte is a white blood cell that engulfs pathogens and destroys them by breaking them down
Inflammation
Fever

7. The Body’s Defenses The Immune System
The immune response is controlled by the immune system, the body’s disease-fighting system
The cells of the immune system can distinguish between different kinds of pathogens. The immune system cells react to each kind of pathogen with a defense targeted specifically at that pathogen
The white blood cells that distinguish between different kinds of pathogens are called lymphocytes

8. The Body’s Defenses The Immune System T Cells B Cells
Major function of the T cells is to identify pathogens and distinguish one kind of pathogen from another
Antigens are molecules that the immune system recognizes either as part of your body or as coming from outside your body
B Cells
Produce proteins that help destroy pathogens
These proteins are called antibodies

9. The Body’s Defenses AIDS: acquired immunodeficiency syndrome
The virus that causes AIDS is called the human immunodeficiency virus, or HIV
How HIV Affects the Body
HIV is the only kind of virus known to attack the human immune system directly and destroy T cells
How HIV is Spread
HIV can spread from one person to another only if body fluids from an infected person come in contact with those of an uninfected person
How HIV is Not Spread

10. Preventing Infectious Disease
Active Immunity
The body produces the antibodies that fight the disease pathogens
A person acquires active immunity when their own immune system produces antibodies in response to the presence of a pathogen
The Immune Response

11. Preventing Infectious Diseases
Vaccination or immunization
Is the process by which harmless antigens are deliberately introduced into a person’s body to produce active immunity
Vaccine usually consists of pathogens that have been weakened or killed but can still trigger the immune system to go into action
When You Do Get Sick
An antibiotic is a chemical that kills bacteria or slows their growth without harming body cells

12. Preventing Infectious Diseases
Passive Immunity
Results when antibodies are given to a person – the person’s immune system does not make them
A person acquires passive immunity when the antibodies that fight the pathogen come from a source other than a person’s body

13. Noninfectious Disease
Noninfectious disease are disease that are not caused by pathogens in the body and cannot be transmitted from person to person
Cardiovascular disease, allergies, diabetes, and caner are some example of noninfectious diseases

14. Noninfectious Disease
Allergies is a disorder in which the immune system is overly sensitive to a foreign substance – something not normally found in the body
An allergy develops in response to various foreign substances that set off a series of reactions in the body

15. Noninfectious Disease
Allergies
Allergens: any substance that causes an allergy
Histamine is a chemical that is responsible for the symptoms of an allergy, such as sneezing and watery eyes
Asthma is a disorder in which the respiratory passages narrow significantly

16. Noninfectious Disease
Diabetes
Insulin enables body cells to take in glucose from the blood and use it for energy
In the condition known as diabetes, either the pancreas fails to produce enough insulin or the body’s cells fail to properly use insulin
As a result, a person with diabetes has high levels of glucose in the blood and may even excrete glucose in the urine. The person’s body cells, however, do not have enough glucose
Effects of Diabetes
Forms of Diabetes

17. Noninfectious Disease
Cancer is a disease in which cells multiply uncontrollable, over and over, destroying healthy tissue in the process
How Cancer Develops
As cells divide over and over, they often form abnormal tissue masses called tumors
Causes of Cancer
Some substances or factors in the environment, called carcinogens, can cause cancer (tar, ultraviolet light)
Cancer Treatment
Cancer Prevention