Section 1 Infectious Disease

Chapter 5 Fighting Disease

Understanding Infectious Disease

When you have an infectious disease, pathogens have gotten inside your body and caused harm.

Pathogen: Organisms that cause disease.

Infectious Disease: Disease caused by the presence of a living thing within the body.

Understanding Infectious Disease

Famous People 1860’s – 1880’s

Joseph Lister: British Surgeon hypothesized that microorganisms caused infections. (washed his hands and equipment, what a brilliant man)

Louis Pasteur: Showed that microorganisms cause certain kinds of diseases. Killing microorganisms can prevent disease.

Robert Koch: demonstrated that each infectious disease is caused by a specific kind of pathogen.

Kinds of Pathogens

There are 4 major groups of human pathogens.

BacteriaVirusesFungiProtists

Kinds of Pathogens

Bacteria: one-celled microorganisms, damage Body cells directly, and indirectly through toxins.

Toxin: Poison, that attacks kills or damages cells.

Kinds of Pathogens

Kinds of Pathogens

Viruses: tiny particles, much smaller than bacteria. Cannot reproduce unless they are inside a living cell.

Colds and Flu are caused by viruses.

Over 200 kinds.

Meds don’t work, body must kill with immune system.

Kinds of Pathogens

Kinds of Pathogens

Fungi:

molds and yeast

grows in warm, dark, and moist areas.

Examples: athlete’s foot and ringworm.

Kinds of Pathogens

Kinds of Pathogens

Protists: eukaryotic organisms unicellular, and multicellular organisms, such as the protozoans, slime molds, brown algae, and red algae.

Examples:

MalariaAfrican Sleeping SicknessAmebic Dysentery

Kinds of Pathogens

How Pathogens Are Spread

Pathogens can spread through contact with:

Infected personSoilFoodWaterContaminated objectInfected animal

Section 2 The Body’s Defenses

Chapter 5 Fighting Disease

Barriers That Keep Pathogens Out

First line of Defense:

Surfaces of SkinBreathing PassagesMouthStomach

These barriers trap and kill most all pathogensthat try to enter the body.

Barriers That Keep Pathogens Out

Skin:

Chemicals in oil and sweatFall off with dead skinTightly lined skin cells

Normally enters through skin cuts

Skin

Barriers That Keep Pathogens Out

Breathing Passages:

Contain mucus and ciliaSneeze and Cough

Breathing Passages

Barriers That Keep Pathogens Out

Mouth & Stomach:

Saliva contains destructive chemicals

Acid in stomach

Mouth & Stomach

Stomach

The Inflammatory Response

In the inflammatory response, fluid and white blood cells leak from blood vessels into nearby tissues. The white blood cells then fight the pathogens.

The Inflammatory Response

White Blood Cells

Phagocyte: white blood cell that engulfs pathogens and destroys them by breaking them down.

White Blood Cell

White Blood Cell

The Inflammatory Response

Inflammation

Blood vessels widenBigger area faster responseExtra fluid, creates a swollen area

The Inflammatory Response

Fever

Chemicals produce feverIncreased temp restricts infections ability to spread reproduce & grow.

Fever

The Immune System

The cells of the immune system can distinguish between different kinds ofpathogens. The immune system cellsReact to each kind of pathogen with adefense targeted specifically at that pathogen.

Immune System

The Immune System

T Cell

To identify pathogens and distinguish one kind of pathogen form another.

T Cell

The Immune System

B Cell

Produces proteins that help destroy pathogens.

Antibodies: are made for specific antigens, marks them for death.

B Cell

AIDS

Disease caused by the virus, HIV.

HIV is the only kind of virus known to attack the human immune system directly and destroy T cells.

AIDS

Section 3 Preventing Infectious Disease

Chapter 5 Fighting Disease

Active Immunity

Immunity: The body’s ability to Destroy pathogens before they can cause disease.

Active Immunity

Active Immunity: Your own immune system produces antibodies in response to the presence of a pathogen.

Active ImmunityThe Immune Response

T cells and B cells keep the “memory” of how to destroy pathogens that have all ready entered the body.

This response can last for life.

Active ImmunityVaccination

The process by which harmless antigens are deliberately introduced into a person’s body to produce active immunity.

Vaccine: consists of pathogens that have been weakened or killed but can still trigger the immune system.

Vaccination

Active ImmunityWhen You Do Get Sick

Antibiotic: chemical that kills bacteria or slows their growth with out harming body cells.

Nothing you can take for a viral infection.

Antibiotic

Passive ImmunityPassive Immunity

A person acquires passive immunity when the antibodies that fight the pathogen come from a source other than the person’s body.

Section 4 Noninfectious Disease

Chapter 5 Fighting Disease

Noninfectious Disease

Diseases that are not caused by pathogens in the body.

Can not be transmitted from person to person.

AllergiesAn allergy develops in response to various foreign substances that set off a series of reactions in the body.

Allergens: A substance that causes an allergy.

Histamine: a chemical that is responsible For the symptoms of an allergy, such as Sneezing and watery eyes.

Allergy

Allergy

Allergens

Histamine

AllergiesAsthma:

A disorder in which the respiratory passages narrow significantly.

Can be brought on by stress and exercise.

Asthma

DiabetesHigh 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.

Insulin: enables body cell to take in glucose from the blood and use it for energy.

Glucose

Insulin

Insulin

Effect of DiabetesShort-Term Effects:

Weight lossFeeling weakHungry all the timeFeeling thirsty

Long-term Effects:BlindnessKidney FailureHeart Disease

Forms of DiabetesType I

Begins in childhood or early adulthood

Pancreas produces little or no insulinType II

Develops during adulthoodPancreas does not make enough

insulin, or body cells do not respond normally to insulin

Control through proper diet, and exercise.

Type I Diabetes

Type II Diabetes

CancerA disease in which cells multiply uncontrollably, over and over, destroying healthy tissue in the process.

CancerHow Cancer Develops

Tumors: Cells dividing out of control, not all tumors are cancerous. Cancer cells break off and destroy healthy tissue.

Blood and Lymph vessels can carry cancer cells around the body for new tumors to form.

Tumors

CancerCauses of Cancer

Tumors: Cells dividing out of control, not all tumors are cancerous. Cancer cells break off and destroy healthy tissue.

Blood and Lymph vessels can carry cancer cells around the body for new tumors to form.

CancerCancer Treatment

Surgery: Removal

Drugs: Use of chemicals to destroy cancer cells.

Radiation: High-energy waves to kill cancer cells, in specific spots.

CancerCancer Prevention

Avoid Carcinogens

Low-Fat Diet

Regular Checkups… Catch it early

Section 5 Cancer and the Environment

Chapter 5 Fighting Disease

Linking Cancer to the Environment

First Studies

1700’sChimney SweepsSkin Cancer

Linking Cancer to the Environment

A Link Between Soot and Cancer

Percivall PottCarcinogens in sootSame stuff in in the tar of

cigarette smoke

Linking Cancer to the Environment

Carcinogens in the Environment

The environment many contain carcinogens. To reduce the risk of cancer, carcinogens need to be removed or people need to be protected from them. (EPA)

Environmental Carcinogens Today

Ultraviolet Light

Skin CancerOzone going away

Environmental Carcinogens Today

Vinyl Chloride

Colorless gasPVC – plastic products

pipes, coating for wires, packaging, upholstery,

house wares, car parts.

Liver, brain, lung cancer

Environmental Carcinogens Today

Arsenic

Naturally Occurs in soil and rock

Wood Preservative (CCA) pressure treat

Liver, Bladder, Kidney, and Lung cancer