COMMUNICABLE
DISEASES
 Disease causing bacteria, can produce TOXINS.
Toxins-Substance that kills cells and interferes functions.
Can be treated with antibiotics
WHAT ARE THEY?
 Communicable Disease-disease that is spread from one living
organism to another or through environment.
 Also known as contagious and infectious disease.
HOW DO THEY OCCUR?
 Pathogens enter the body
 Pathogens-micro-organisms that causes disease.
 If body does not fight off this pathogen it could lead to an
INFECTION
 Infection--condition that occurs when pathogens in the body
multiply and damage body cells.
VIRUSES
 The most common communicable disease
• Cold and Flu
• Viruses can only reproduce when they invade the cells of living
organisms.
• Unable to treat a virus with antibiotics
TYPES OF VIRUSES
 Common Cold
 Influenza (flu)
 Measles
 Polio
PROCESS OF A VIRUS
 1. Virus enter the body
 2. Virus invade cells of living organisms
 3. once virus invades cell it begins to multiply
 4. New viruses burst out of cells and begin to take over other cells
 5. Immune system kicks into actions and stops the virus
BACTERIA
 Bacteria-Micro-ogranisms that live almost everywhere on earth.
• Most are harmless
• Some are help (help digest food)
• Some cause disease
TYPES OF BACTERIA
 Strep throat
 Meningitis
OTHER TYPES OF
PATHOGENS
 1. Fungi-plantlike organisms that can causes diseases of the lungs,
mucous membranes and the skins.
• Athletes foot is a common fungi
HOW DISEASES SPREAD
 1. Direct Contact
• Touching, biting, kissing
-Puncture wounds-stepping on rusty nails
-Contact with infected animals-animal bites and scratches can
sometimes transmit diseases.
INDIRECT CONTACT
 Contaminated Objects-Can be spread from contaminated objects
such as doorknob.
• What could you do to prevent this????
Vectors-Organisms that carry and transmits pathogens to humans or
other animals.
Ex. Flies mosquitoes, ticks.
-Contaminated food or water-If food is improperly handled or stored,
harmful bacteria could form.
AIRBORNE TRANSMISSION
 When infected person sneezes or coughs pathogens are released.
• Can travel as far as 10 feet
• Ex. Chicken Pox, flu
TAKING PRECAUTIONS
 No guaranteed way to avoid a communicable disease completely.
 -Wash Hands (soap and warm water)
Before you eat
After handling pets
Touching objects handled by infected person
PROTECT YOURSELF FROM
VECTORS
 Limit time you spent outdoors, after dark
 Wear protective clothing
• Sweat pants, sweat shirt
Use repellent
THE IMMUNE SYSTEM
 Review:
 What is a pathogen???
 Where can we find them???
THE 5 BARRIERS
 The body has 5 barriers that keep pathogens out
 1. TEARS
• TEARS COVER AND PROTECT THE EYE FROM DUST AND
PATHOGENS.
• AS TEARS FLOW THEY CARRY FOREIGN MATERIAL AWAY
FROM THE EYE.
5 BARRIERS CONT…
 #2: SALIVA:
• SALIVA HAS CHEMICAL THAT’S KILL PATHOGENS IN
YOUR MOUTH
#3: SKIN
-SKIN PROVIDES PROTECTIVE SURFACE THAT KEEPS
PATHOGENS FROM ENTERING BLOOD.
-GETTING A CUT OR SCRAPE COULD LEAD TO
PATHOGENS ENTERING THE BODY
5 BARRIERS CONT…
 #4: MUCOUS MEMBRANE
• MUCOUS MEMBRANE ARE THE SOFT SKIN THAT LINE
THE NOSE, MOUTH, AND EYES.
• COATED WITH FLUID CALLED MUCUS, THAT TRAP
PATOGENS
• WHEN YOUR SNEEZE, COUGHT OR CLEAR THROAT,
BODY GETS RID OF MUCOUS
5 BARRIERS CONT…
 #5:
• STOMACH ACID:
• STOMACH ACID KILLS MANY OF THE PATHOGENS THAT
GET PAST SALIVDA AND MUCOUS MEMBRANE.
 WHAT HAPPENS IF PATHOGENS GET PAST 5
BARRIERS??
 Immune system kicks in.
 Immune System: combination of body defenses made up of cells,
tissues, and organs that fight pathogens in the body.
2 RESPONSES
 The immune system has 2 responses.
 Specific vs Non-specific
NON-SPECIFIC
 When you get a splinter in your finger, dirt and pathogens on the
splinter also enter the system.
• Body responds with a non-specific response as it would with any
foreign object entering the body.
What usually happens when someone gets a splinter?
SPECIFIC RESPONSE
 Pathogens sometimes get past the non-specific response
 When this happens SPECIFIC RESPONSE kicks into action.
 Specific response attacks a particular pathogen.
 Your immune system can recognize certain pathogens!!
 Once immune system has created a specific response it will
recognize them.
LYMPHATIC SYSTEM
 Lymphatic System-secondary circulatory system that helps the
body fight pathogens and maintain fluid balance.