Chapter 13- Infectious Diseases

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Chapter 13- Infectious Diseases

• Section 1- What are Infectious Diseases?
• Section 2- Protecting Yourself from Infectious
  Diseases
• Section 3- Common Infectious Diseases

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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

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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

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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.

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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

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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

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Fungi

• An organism that absorbs and uses the nutrients
  of living or dead organisms
• Athletes 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

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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

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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

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• Bacteria Viruses Fungi

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• Protozoans Parasites

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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

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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

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Protecting Yourself from Infectious Diseases

• Chapter 13 Section 2

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How Your Body Fights Disease

• Your bodys 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

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Inflammatory Response

• Your bodys 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

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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.

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• 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)

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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

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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.

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What to Do When You Are Sick

• Stay home
• Get plenty of rest
• Try not to pass your illness to others
• Dont share personal items
• Cover your mouth
• Drink plenty of fluids
• See a doctor and take the doctors advice
• Take medications that are prescribed to you
• Wash your hands frequently