Chapter 13- Infectious Chapter 13- Infectious DiseasesDiseases

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

DiseasesDiseasesSection 3- Common Infectious DiseasesSection 3- Common Infectious Diseases

Objectives for Chapter 13Objectives for Chapter 13

Identify different agents that cause infectious Identify different agents that cause infectious diseasesdiseasesList four ways infectious diseases spreadList four ways infectious diseases spreadDescribe different treatments for infectious Describe different treatments for infectious diseasesdiseasesDescribe how the body fights infectious diseasesDescribe how the body fights infectious diseasesSummarize five things a person can do to stay Summarize five things a person can do to stay wellwell

Objectives cont.Objectives cont.

Describe how immunity to a disease Describe how immunity to a disease develops develops

State three things you should do when you State three things you should do when you are sickare sick

List three things you can do to prevent the List three things you can do to prevent the spread of infectious diseasesspread of infectious diseases

Infectious DiseasesInfectious Diseases

An infectious disease is any disease that An infectious disease is any disease that is caused by an agent that has invaded is caused by an agent that has invaded the body. the body. Examples of infectious diseases: colds, Examples of infectious diseases: colds, the flu, head lice, and tuberculosisthe flu, head lice, and tuberculosisAll infectious diseases are caused by All infectious diseases are caused by pathogenspathogensA pathogen is any agent that causes A pathogen is any agent that causes disease. disease.

BacteriaBacteria

Tiny, single-celled organisms Tiny, single-celled organisms

Most bacteria are harmless, many are Most bacteria are harmless, many are actually helpfulactually helpful

Some bacteria make you sick when they Some bacteria make you sick when they grow inside your bodygrow inside your body

Some bacteria give off poisons, while Some bacteria give off poisons, while other bacteria enter and damage cellsother bacteria enter and damage cells

Tuberculosis, tetanus, and sinus infectionsTuberculosis, tetanus, and sinus infections

VirusesViruses

Smaller than bacteriaSmaller than bacteriaTiny, disease-causing particles made up of Tiny, disease-causing particles made up of genetic material and a protein coatgenetic material and a protein coatThe genetic material contains instructions The genetic material contains instructions for making more virusesfor making more virusesViruses survive and replicate only inside Viruses survive and replicate only inside living cellsliving cellsChicken pox, colds, the flu, measles, and Chicken pox, colds, the flu, measles, and HIVHIV

FungiFungi

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

Athlete’s foot- caused by a fungus that Athlete’s foot- caused by a fungus that lives and feeds on your feet and makes lives and feeds on your feet and makes them burn and itchthem burn and itch

Ringworm- a fungus responsible for a Ringworm- a fungus responsible for a scaly, circular rashscaly, circular rash

ProtozoansProtozoans

Single-celled, microscopic organisms that Single-celled, microscopic organisms that are larger and more internally complex are larger and more internally complex than bacteriathan bacteria

Protozoans account for diseases that are Protozoans account for diseases that are the leading causes of death throughout the leading causes of death throughout some parts of the worldsome parts of the world

Malaria is a disease caused by protozoansMalaria is a disease caused by protozoans

ParasitesParasites

Animal parasites get their energy and Animal parasites get their energy and nutrients by feeding on other living thingsnutrients by feeding on other living things

Examples of harmful animal parasites Examples of harmful animal parasites include head lice, tapeworms, and certain include head lice, tapeworms, and certain roundwormsroundworms

BacteriaBacteria Viruses Viruses Fungi Fungi

ProtozoansProtozoans ParasitesParasites

How are Infectious Diseases How are Infectious Diseases Spread?Spread?

Person-to-person- through the air or contact with Person-to-person- through the air or contact with another personanother personexamples: flu, colds, measlesexamples: flu, colds, measlesFood-and-water- through the food you eat or the Food-and-water- through the food you eat or the water you drink.water you drink.examples: hepatitis A, botulism, typhoid, choleraexamples: hepatitis A, botulism, typhoid, choleraEnvironment- from the objects around you Environment- from the objects around you example: tetanusexample: tetanusAnimals- from animals or insectsAnimals- from animals or insectsexamples: ringworm, malaria, Lyme diseaseexamples: ringworm, malaria, Lyme disease

Treating Infectious DiseasesTreating Infectious Diseases

Bacterial diseases- antibioticsBacterial diseases- antibioticsViral diseases- most medications rely on Viral diseases- most medications rely on relieving symptoms and stopping the relieving symptoms and stopping the production of viruses inside the human production of viruses inside the human cellscellsFungal infections- over-the-counter Fungal infections- over-the-counter antifungal medicineantifungal medicineProtozoan infections- prevention is the keyProtozoan infections- prevention is the keyParasitic infections- medicationsParasitic infections- medications

Protecting Yourself from Protecting Yourself from Infectious DiseasesInfectious Diseases

Chapter 13 Section 2Chapter 13 Section 2

How Your Body Fights DiseaseHow Your Body Fights Disease

Your body’s first line of defense includes your Your body’s first line of defense includes your skin, mucous membranes, and chemicals.skin, mucous membranes, and chemicals.

Skin keeps pathogens from entering your bodySkin keeps pathogens from entering your body

Mucous membranes, such as your nose, mouth, Mucous membranes, such as your nose, mouth, and throat, trap pathogens and move them to and throat, trap pathogens and move them to your stomach to be destroyed.your stomach to be destroyed.

Your sweat, tears, and stomach acid are all Your sweat, tears, and stomach acid are all chemicals that kill bacteriachemicals that kill bacteria

Inflammatory ResponseInflammatory Response

Your body’s second line of defense is Your body’s second line of defense is inflammation.inflammation.

Inflammation- a reaction to injury or infection Inflammation- a reaction to injury or infection that is characterized by pain, redness, or that is characterized by pain, redness, or swelling.swelling.

This is caused by the small blood vessels that This is caused by the small blood vessels that expand to bring more blood to the injured areaexpand to bring more blood to the injured area

This response shows that your body is attacking This response shows that your body is attacking pathogenspathogens

Immune SystemImmune System

This is your third line of defenseThis is your third line of defense

The immune system is made up of certain The immune system is made up of certain types of blood cells and certain proteins types of blood cells and certain proteins called antibodies.called antibodies.

These infection-fighting cells move These infection-fighting cells move through the lymphatic system, a network through the lymphatic system, a network of vessels that carry a clear fluid called of vessels that carry a clear fluid called lymph throughout the body.lymph throughout the body.

White blood cells are cells in the blood White blood cells are cells in the blood whose primary job is to defend the body whose primary job is to defend the body against disease.against disease.

When you are sick, your lymph nodes When you are sick, your lymph nodes often swell because of the growing often swell because of the growing number of white blood cells fighting the number of white blood cells fighting the infection.infection.

Active immunity is established when the Active immunity is established when the body produces antibodies that recognize body produces antibodies that recognize future pathogens (either by having the future pathogens (either by having the disease or by vaccination)disease or by vaccination)

What You Can Do to Stay WellWhat You Can Do to Stay Well

Protect yourselfProtect yourselfEat a healthy, balanced dietEat a healthy, balanced dietDrink waterDrink waterReduce your stress levelsReduce your stress levelsExercise regularlyExercise regularlyGet regular medical checkupsGet regular medical checkupsTry to avoid close contact with sick peopleTry to avoid close contact with sick peopleGet enough sleepGet enough sleep

Get VaccinatedGet Vaccinated

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

What to Do When You Are SickWhat to Do When You Are Sick

Stay homeStay homeGet plenty of restGet plenty of restTry not to pass your illness to othersTry not to pass your illness to othersDon’t share personal itemsDon’t share personal itemsCover your mouthCover your mouthDrink plenty of fluidsDrink plenty of fluidsSee a doctor and take the doctor’s adviceSee a doctor and take the doctor’s adviceTake medications that are prescribed to youTake medications that are prescribed to youWash your hands frequentlyWash your hands frequently