Section 1 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.

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.

There are 4 major groups of human pathogens. Bacteria Viruses Fungi Protists

Bacteria: one-celled microorganisms, damage Body cells directly, and indirectly through toxins. Toxin: Poison, that attacks kills or damages cells.

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.

Fungi: molds and yeast grows in warm, dark, and moist areas. Examples: athlete’s foot and ringworm.

Protists: eukaryotic organisms unicellular, and multicellular organisms, such as the protozoans, slime molds, brown algae, and red algae. Examples: Malaria African Sleeping Sickness Amebic Dysentery

Pathogens can spread through contact with: Infected person Soil Food Water Contaminated object Infected animal

Section 2 The Body’s Defenses

First line of Defense: Surfaces of Skin Breathing Passages Mouth Stomach These barriers trap and kill most all pathogens that try to enter the body.

Skin: Chemicals in oil and sweat Fall off with dead skin Tightly lined skin cells Normally enters through skin cuts

Breathing Passages: Contain mucus and cilia Sneeze and Cough

Mouth & Stomach: Saliva contains destructive chemicals Acid in stomach

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

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

Inflammation Blood vessels widen Bigger area faster response Extra fluid, creates a swollen area

Fever Chemicals produce fever Increased temp restricts infections ability to spread reproduce & grow.

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.

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

B Cell Produces proteins that help destroy pathogens. Antibodies: are made for specific antigens, marks them for death.

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.

Section 3 Preventing Infectious Disease

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

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

The 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.

Vaccination 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.

When 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.

Passive 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

Diseases that are not caused by pathogens in the body. Can not be transmitted from person to person.

An 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.

Asthma: A disorder in which the respiratory passages narrow significantly. Can be brought on by stress and exercise.

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

Short-Term Effects: Weight loss Feeling weak Hungry all the time Feeling thirsty Long-term Effects: Blindness Kidney Failure Heart Disease

Type I Begins in childhood or early adulthood Pancreas produces little or no insulin Type II Develops during adulthood Pancreas does not make enough insulin, or body cells do not respond normally to insulin Control through proper diet, and exercise.

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

How 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.

Causes 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.

Cancer Treatment Surgery: Removal Drugs: Use of chemicals to destroy cancer cells. Radiation: High-energy waves to kill cancer cells, in specific spots.

Cancer Prevention Avoid Carcinogens Low-Fat Diet Regular Checkups… Catch it early

Section 5 Cancer and the Environment

First Studies 1700’s Chimney Sweeps Skin Cancer

A Link Between Soot and Cancer Percivall Pott Carcinogens in soot Same stuff in in the tar of cigarette smoke

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)

Ultraviolet Light Skin Cancer Ozone going away

Vinyl Chloride Colorless gas PVC – plastic products pipes, coating for wires, packaging, upholstery, house wares, car parts. Liver, brain, lung cancer

Arsenic Naturally Occurs in soil and rock Wood Preservative (CCA) pressure treat Liver, Bladder, Kidney, and Lung cancer