INFECTIOUS DISEASE- passed from person to

person

Pathogens• Bacteria-1. Environment- warm, moist, dark2. Good bacteria- yogurt, cheese, penicillin3. Bad bacteria- produces a TOXIN (poison)Diseases: tetanus, strep throat, food poisoning,

gonorrhea, syphilis, diphtheria

• Virus- smallest pathogen

1. Needs a “host” cell

Diseases: cold, flu, warts, chicken pox, mono, cold sore, small pox, measles, mumps

• Fungi- microscopic plantlike organism

1. Environment- dark, damp

2. Good fungi- yeast, mushroom

Diseases: ringworm, athletes foot

• Protist- single celled, larger than bacteria

1. Commonly found in tropical countries

Diseases: malaria, dysentery

• Parasite- usually visible without a microscope

1. Feed on others

Disease: trichinosis, crabs, tape worm

Transmission: ways diseases are spread.

• Direct Contact- physical contact with infected person: hand shake, hug, kiss

• Indirect Contact- close contact with infected person: sneeze, cough

• Contact with Objects- drinks, cans, pencils, silverware, phones, hats, combs

• Contact with animals- bites (rabies) stings (malaria)

Carriers

• People who can give a disease to others, yet show NO sign or symptom of the disease. They pass it on to others who become ill from the disease.

Immunity: the body’s ability to fight off infection.

Things that may affect your immunity level:

1. Poor nutrition

2. Chronic illness

3. Drug use

4. Overweight

5. Stress

Preventing Infectious Disease

1. Eat well balances meals

2. Get 8 hours of sleep

3. Exercise

4. Avoid stress

5. Do not share items that transfer pathogens

6. Avoid substance abuse

7. Wash your hands / keep clean

8. Get immunizations

3 Lines of the Body’s Defenses

1st Line- Structural (physical)1.Skin2.Mucous Membrane3.Lachrymal glands- tears4.Cilia5.Cerumen- earwax6.Salivary glands- saliva7.Hydrochloric acid- stomach8.Reflexes- sneezing, coughing, blinking, fever

2nd Line- CellularLYMPH SYSTEM- a network of vessels that collect fluid from the tissues in your body and return it to your bloodstream.

Lymphocytes- white blood cells that carry out most of the immune systems functions

1.B lymphocytes (B cells)- produce ANTIBODIES

2.T lymphocytes (T cells)- live in the blood and lymph system

Helper T- identify pathogens

Killer T- kill pathogens

Memory cells- remember how to fight the disease. Last a life time

Circulatory System- (blood)

White Blood Cells called PHAGOCYTES rush to the infected area and destroy pathogens. Phagocytes “eat up” pathogens

This is what happens when a pathogen enters your body (cut, scrape, breath it in)

1. Damaged cells release chemicals 2. Blood vessels and glands in the injured area

become enlarged3. Fluid leaks out of the blood vessels along with

PHAGOCYTES4. Phagocytes eat up pathogen5. Area becomes swollen /sore/ inflamed6. The fluid, phagocytes, and dead cells accumulate,

making a thick white liquid called “pus”7. Eventually the cellular process heals the damage

and it goes away

3rd Line- Immune System

• If a pathogen enters your body for the first time, your immune system must recognize it, and build an arsenal of weapons to fight it. This takes time- this time allows the pathogen to multiply and make you sick.

• If a pathogen that has previously entered your body comes back and enters again, your immune system will quickly recognize it and launch an attack. This generally occurs so quickly you will never become ill.

Types of Immunity

• Passive Immunity- will not last forever1. Killed virus vaccine- need a booster shot flu, tetanus2. Mom at birth- she has memory cells in her

blood• Active Immunity- will last a lifetime1. Live virus vaccine- mumps, measles2. Get the disease

11 Infectious Diseases

1. Rubella (German Measles) danger to pregnant women= birth defects

VIRUS- indirect contactFever, rash better in a few daysVaccination- MMR

2.Polio- stiffness in back and legs=paralysisVIRUS- indirect contactVaccine= oral

3. Diphtheria- coughing- grey membrane grows over throat- death

BACTERIA- indirectVaccine- DPT4. Pertussis (Whooping Cough)-cough-

spasms-lungs collapseBACTERIA-indirectVaccine-DPT5. Tetanus (Lockjaw)- puncture wound.

Muscles lock can cause deathBACTERIA- puncture woundVaccine-DPT needs booster shot every 6-8

years

6. Cold- VIRUS- indirectNO CUREMedication for symptoms but does not cure7. Influenza (Flu) body aches-high fever-

can kill----do not take aspirinVIRUS- indirectVaccine- Flu Shot8.Hepatitis (A, B, C) damages the liverVIRUSA= infected food or waterB&C= BloodVaccine

9.Mononucleosis (mono) need a blood test to identify- last for 3-6 weeks

Tired, swollen glands, sore throatVIRUS- salivaNo medicine- bed rest and good nutrition10. Tuberculosis (TB) cough- weight loss, blood

coughed upNeed blood test and chest x-rayBACTERIA- indirectVaccine11. Smallpox- abdominal pain, scabbing, can dieVIRUS- DIRECT CONTACTVACCINE=====DEAD DISEASE