1. Chapter 13- Infectious Diseases
Section 1- What are Infectious Diseases?
Section 2- Protecting Yourself from Infectious Diseases
Section 3- Common Infectious Diseases

2. Objectives for Chapter 13
Identify different agents that cause infectious diseases
List four ways infectious diseases spread
Describe different treatments for infectious diseases
Describe how the body fights infectious diseases
Summarize five things a person can do to stay well

3. Objectives cont. Describe how immunity to a disease develops
State three things you should do when you are sick
List three things you can do to prevent the spread of infectious diseases

4. Infectious Diseases
An infectious disease is any disease that is caused by an agent that has invaded the body.
Examples of infectious diseases: colds, the flu, head lice, and tuberculosis
All infectious diseases are caused by pathogens
A pathogen is any agent that causes disease.

5. Bacteria Tiny, single-celled organisms
Most bacteria are harmless, many are actually helpful
Some bacteria make you sick when they grow inside your body
Some bacteria give off poisons, while other bacteria enter and damage cells
Tuberculosis, tetanus, and sinus infections

6. Viruses Smaller than bacteria
Tiny, disease-causing particles made up of genetic material and a protein coat
The genetic material contains instructions for making more viruses
Viruses survive and replicate only inside living cells
Chicken pox, colds, the flu, measles, and HIV

7. Fungi
An organism that absorbs and uses the nutrients of living or dead organisms
Athlete’s foot- caused by a fungus that lives and feeds on your feet and makes them burn and itch
Ringworm- a fungus responsible for a scaly, circular rash

8. Protozoans
Single-celled, microscopic organisms that are larger and more internally complex than bacteria
Protozoans account for diseases that are the leading causes of death throughout some parts of the world
Malaria is a disease caused by protozoans

9. Parasites
Animal parasites get their energy and nutrients by feeding on other living things
Examples of harmful animal parasites include head lice, tapeworms, and certain roundworms

10. Bacteria Viruses Fungi

11. Protozoans Parasites

12. How are Infectious Diseases Spread?
Person-to-person- through the air or contact with another person
examples: flu, colds, measles
Food-and-water- through the food you eat or the water you drink.
examples: hepatitis A, botulism, typhoid, cholera
Environment- from the objects around you example: tetanus
Animals- from animals or insects
examples: ringworm, malaria, Lyme disease

13. Treating Infectious Diseases
Bacterial diseases- antibiotics
Viral diseases- most medications rely on relieving symptoms and stopping the production of viruses inside the human cells
Fungal infections- over-the-counter antifungal medicine
Protozoan infections- prevention is the key
Parasitic infections- medications

14. Protecting Yourself from Infectious Diseases
Chapter 13 Section 2

15. How Your Body Fights Disease
Your body’s first line of defense includes your skin, mucous membranes, and chemicals.
Skin keeps pathogens from entering your body
Mucous membranes, such as your nose, mouth, and throat, trap pathogens and move them to your stomach to be destroyed.
Your sweat, tears, and stomach acid are all chemicals that kill bacteria

16. Inflammatory Response
Your body’s second line of defense is inflammation.
Inflammation- a reaction to injury or infection that is characterized by pain, redness, or swelling.
This is caused by the small blood vessels that expand to bring more blood to the injured area
This response shows that your body is attacking pathogens

17. Immune System This is your third line of defense
The immune system is made up of certain types of blood cells and certain proteins called antibodies.
These infection-fighting cells move through the lymphatic system, a network of vessels that carry a clear fluid called lymph throughout the body.

18. White blood cells are cells in the blood whose primary job is to defend the body against disease.
When you are sick, your lymph nodes often swell because of the growing number of white blood cells fighting the infection.
Active immunity is established when the body produces antibodies that recognize future pathogens (either by having the disease or by vaccination)

19. What You Can Do to Stay Well
Protect yourself
Eat a healthy, balanced diet
Drink water
Reduce your stress levels
Exercise regularly
Get regular medical checkups
Try to avoid close contact with sick people
Get enough sleep

20. Get Vaccinated
Vaccines are substances usually prepared from killed or weakened pathogens or from genetic material and that is introduced into a body to produce immunity.
When a vaccine is injected, the immune system responds by making white blood cells called memory cells.
In the future, if the pathogen enters the body, the memory cells and their antibodies fight the pathogen before it can cause disease.

21. What to Do When You Are Sick
Stay home
Get plenty of rest
Try not to pass your illness to others
Don’t share personal items
Cover your mouth
Drink plenty of fluids
See a doctor and take the doctor’s advice
Take medications that are prescribed to you
Wash your hands frequently