Diseases

• Infectious diseases=organisms that enter, live in and multiply within the body

• Pathogens=organisms that cause disease

*If they enter your body and multiply they

create an infection and you develop a disease

Pathogens• Bacteria=simple, single celled organisms that

live almost anywhere (air, surfaces, food)

Under a microscope, they look like balls or rods. They are so small that a line of 1,000 could fit across a

pencil eraser. Most bacteria won't hurt you less than 1 percent makes people sick. Many are helpful. Some

bacteria help to digest food and destroy disease-causing cells. Bacteria are also used in making

healthy foods like yogurt and cheese.

Bacterial diseases=Strep Throat, Food poisoning, and meningitis

Viruses

• The smallest pathogens, can multiply only by entering a living cell and taking over the cells reproductive mechanisms, resulting in cell death.

Viral diseases have no cure so the body must fight off the infection

Viral infections=common cold, HIV, AIDS

Protozoan• Single-celled organisms that have the ability to

move through fluids in search of food.

Protozoan diseases=Toxoplasmosis, malaria,

amoebic dysentery

Fungi• Simple organisms related to molds that live in

dark warm moist areas.

Fungal Infections=athletes foot, ringworm

yeast infection

Cured with antifungal creams or sprays

Body Defenses Against Diseases

Your body protects itself from infection in 3 ways.

• Physical & Chemical defenses

• Inflammation

• Immune System

Physical & Chemical Defenses• Skin=1st line of defense

• Sweat=contains acids that kill bacteria• Mouth, eyes, nose=contains mucous membranes• Cilia=tiny hair like structures that line air passages

• Stomach acids=acid kills bacteria

• Digestive Tract=flushes away bacteria

• Urine=kills pathogens with acid

InflammationBody’s response to all cuts and

internal damagePhagocytes=W.B.C. eat up foreign cells and kill

unwanted pathogens, gives off a clear liquid or pus

Immune systemMost sophisticated line of defense

Can seek out and destroy pathogens

“B” Cells “T” Cells

Generals Soldiers

Spread of Infectious Disease• Direct Contact=touching, hugging, kissing, sex• Indirect Contact=sneezing, coughing, contact

with infected person’s blood• Contact w/objects=doorknobs, eating & drinking utensils contaminated food & drink• Contact w/animals=bites, tick, mosquito, animal• Contact w/Enviro. Sources=tetanus, salmonella

botulism

Infectious DiseasesCommon Cold

• No Cure,

• spread by touching contaminated objects

• coughing and sneezing

• Lasts 3-7 days

• VIRUS

Influenza

• No Cure,

• Spreads like the common cold

• Airborne droplets and contaminated objects

• Fever, sore throat, body aches, cough

• Vaccine available Every Year

• VIRUS

Pneumonia• Infection of the lungs

• Chronic Coughing

• VIRUS, BACTERIA, FUNGI

Rubella• Known as Germen Measles

• Fever, rash, coughing, sneezing,

• sore throat, swollen glands

• Vaccine

• VIRUS

Hepatitis• Inflammation of the Liver• Fever, nausea, pain in abdomen, • jaundice, brown urine,

• Symptoms appear 3-6 weeks after exposure

Hep. A=contaminated food & waterHep. B=contaminated blood & body fluids

VACCINE is availableHep. C=contaminated blood & body fluids

Most Dangerous

Tuberculosis• Highly contagious infection that infects the

lungs.

• Transmitted by coughing or sneezing.

• Fatigue, weight loss fever, chronic cough.

• Treatment=medications up to a year

• BACTERIA

Mononucleosis

• Infection causes swollen lymph nodes, tonsils, and spleen.

• Sever sore throat, extreme fatigue

• 3-6 weeks for symptoms to come to an end.

• Spread through saliva

• VIRUS