Fighting Disease

Fighting DiseaseMr. Gagnon

Human Biology and healthFighting Disease:

6.1 Infectious Disease:Key Terms: - Pathogens - Infectious Disease - Toxin

Key Concepts: - What kinds of organisms cause disease? - Where do pathogens come from?

Surgical HistorySurgery Pre-twentieth CenturySurgery before the 1900s was very risky. Many patients died after surgery.Joseph Lister hypothesized that microorganisms infected his patients.Lister used carbolic acid to sterilize his tools and on bandages post surgery.

Disease and pathogensIllnessKey Advances in UnderstandingFood poisoning and ear infections are caused by living things too small to see.Pathogens- are organisms that cause disease.Infectious disease- is a disease that can be passed on from one organism to another.Lister was influenced by Louis Pasteur who showed that killing microorganisms can prevent the spread of disease.Robert Koch in 1870s and 80s demonstrated that infectious diseases are caused by specific microorganisms.Ecoli, is an example.Kinds of pathogensBacteriaVirusesBacteria are one celled microorganisms.Ear infections, food poisoning, tuberculosis.Pathogens damage cells directly and invade cells, or create a toxin, a poison that damages cells.Viruses cannot reproduce on their own. They invade cells, reproduce, and then spread through the body. Influenza (the flu), Chicken Pox, and AIDS.

How do scientists identify the pathogen that causes a specific disease?

Fungi and protistsFungi (molds, yeasts, mushrooms, other organisms) cause some infectious diseases.Athletes foot is an example of fungal infection. Malaria is caused by protists.

How can you become infected?

Person to Person- through contact with another person.Contaminated Objects- some pathogens survive on surfaces (ie. Desks).Animal Bites- rabies (animals like raccoons) and Lyme disease (deer ticks).Natural Environment- tetanus (soil and water) and botulism (bacteria in food).

Pathogen Comic

Pathogen comic

Pathogen Comic

Human Biology and healthFighting Disease:6..2 The Bodys Defenses:Key Terms: - Inflammatory Response - Phagocyte - Immune Response - Lymphocyte - T Cell - Antigen - B Cell - Antibody - AIDS

Key Concepts: - What is the bodys first line of defense? - What happens during an inflammatory response?- How does the immune system respond to pathogens?

The Bodys Barriers(1st Line of defense)The SkinThe Breathing PassagesOils and sweat battle bacteria on the surface.Pathogens on dead skin cells fall to the ground.Pathogens may enter at open cuts, but scabs form over those surfaces.The nose, pharynx, trachea, and bronchi have mucus and cilia that catch the pathogens.Coughing and sneezing helps expel these pathogens.

The Bodys Barriers(1st Line of defense)Mouth and StomachSaliva contains enzymes that help break down pathogens.

The stomach produces acid to fight pathogens.

Other DefensesInflammation- Fluid and certain types of white blood cells leak from blood vessels into nearby tissue. The WBC then fight the pathogen.Phagocytes are involved in inflammation. They are the WBCs that engulf pathogens and destroy them by breaking them down.

During the Inflammation ResponseBlood vessels widen (dilate).Fluid leaks out of the vessels causing redness and swelling.May cause a fever due to chemical release.

The Immune SystemThe immune response is the bodys 3rd line of defense that is controlled by the immune system.The immune system uses lymphocytes, which are WBCs that identify and destroy pathogens.

T-Cell Lymphocytes are WBCs that distinguish one kind of pathogen from another.Antigens are marker molecules on the exterior of cells that a t-cell recognizes as either part of the body or not.B-Cell Lymphocytes are WBCs that produce chemicals that help destroy pathogens.Antibodies are the chemicals produced by the b-cell lymphocytes sent to destroy the pathogen.

HIV/aidsHIV/AIDS is the acquired immunodeficiency that attacks the immune system.This virus attaches and reproduces within a t-cell lymphocyte.This makes it difficult for the lymphocytes to recognize the pathogens.People who die from AIDS often die from the common cold or flu because the body cannot recognize and fight the pathogens.Human Biology and healthFighting Disease:

6.3 Preventing Infectious Disease:Key Terms: - Immunity - Active Immunity - Vaccination - Vaccine - Passive Immunity - Antibiotic

Key Concepts: - What is active immunity? - What is passive immunity?

Active ImmunityOnce you have the chicken pox virus, do you get it a second time? Why or why not?

Active Immunity occurs when a persons own immune system produces antibodies in response to the presence of a pathogen.

Active immunity is produced by the cells of a persons immune system.

The persons T-Cells and B-Cells remember previous viruses that they had to destroy.Active ImmunityIf a person does not contract a disease, he/she could still become immune.Vaccination is the process by which harmless antigens are deliberately introduced into a persons body to produce active immunity.The vaccine is the substance shot into the vaccinated person that usually consists of pathogens that have been weakened or killed but still triggers the immune system into action.

Passive Immunity Passive Immunity is when someone is given a shot of antibodies after he/she has contracted antigens (ie. Rabies).

Passive immunity occurs when the antibodies that fight the pathogen come from another source rather than from the persons body.

Staying HealthyDont share items that might be contaminated (straws, toothbrushes, or silverware).Keep clean.Cover your mouth when coughing, preferably your elbow.Get 8hr of sleep each night.Eat a well balanced diet.Get regular exercise.Recovering While SickGet plenty of rest.Eat well balanced meals.Drink fluids.Take antibiotics, a chemical that kills bacteria or slows their growth, if instructed by a doctor.There are not medicines for viral illnesses, like the common cold. Get plenty of rest.

Human Biology and healthFighting Disease:6.4 Noninfectious Disease:Key Terms: - Noninfectious Disease - Allergy - Allergen - Histamine - Asthma - Insulin - Diabetes - Cancer - Tumors - CarcinogensKey Concepts: - What is an allergy? - How does diabetes affect the body?

What is a Noninfectious Disease?A Noninfectious Disease is a disease that is not spread from person to person.

Examples: AllergiesDiabetesCancer

What are allergies?An allergy is a disorder in which the immune system is overly sensitive to a foreign substance (something not normally found in the body).

Allergies are caused by allergens, which are any substances that cause an allergy (ie: pollen, dust, molds, some foods, animals, and medicines).

Allergens enter the system through inhalation, ingestion, or touch.

Lymphocytes recognize the allergen and produce antibodies which signals the cells to produce histamine.

Histamine is a chemical responsible for the symptoms of an allergy (sneezing, watery eyes).

Asthma, a disorder in which the respiratory passages narrow significantly, may develop from allergens that are inhaled.

What is Diabetes?Diabetes is the condition in which either the pancreas fails to produce enough insulin or the cells body cant use it properly.As a result, a person with diabetes has high levels of glucose in the blood (high blood sugar) and excretes glucose in their urine. The persons cells do not have enough glucose.Insulin is a chemical made in the pancreas to help take glucose (sugar) from the blood and convert it into energy.Symptoms:Loss of weight, feel weak, hungry all the time, can result in death if not treated right.

What are the 2 Forms of Diabetes?Type 1- is the most serious form in which the pancreas produces little or no insulin. This is childhood or early adulthood diabetes. These patients must take insulin shots.

Type 2- usually develops during adulthood, and the pancreas doesnt produce enough insulin or the bodys cells dont use it properly. These patients might not need to take insulin and can control it through diet and exercise.

CancerCancer is a disease in which cells multiply uncontrollably, over and over, destroying healthy tissue in the process.

The division of cells over and over again forms abnormal tissue mass called a tumor.

Benign tumors do not spread throughout the body, while malignant tumors spread uncontrollably.

Causes of CancerHeredity (susceptibility of getting cancer).

Carcinogens are substances or factors found in the environment that cause cancer (ie: UV rays, tar from cigarettes, etc.).

Cancer PreventionAvoid all forms of tobaccoReduce exposure to sunlightLow fat diet w/ plenty of fruits and veggiesRegular medical checkups for early detection