Transcript 8_Infectious_Diseases_x - Clinton Public School District

Infectious Diseases
Bell Work:
Do Now:
Name 4 pathogens
Name an infectious
disease caused by each
Non-Infectious Disease
Not caused by pathogens
Cannot be transmitted to other people
Risk factors:
Genetics
Life-style
Environmental factors
Examples:
Heart Disease, Cancer, Diabetes
What is an Infectious Disease?
Illnesses that Pass from One organism to another
Caused by Pathogens
4 Main Types of Pathogens:
Virus
Bacteria
Fungi
Parasites
Infectious Disease Can
Spread by:
Contact with Infected Person:
Direct Touching
Touching, hugging
Cold sores from Kissing
Indirect Touching:
Inhaling drops of moisture (from sneezing or coughing)
Cold & Flu
Contact with Contaminated Object
Eating Utensils
Strep Throat and Mononucleosis
Anything that has been coughed or sneezed on
Eating or Drinking Food Prepared by Infected Person
Infectious Disease Can
Spread by:
Contact with Infected Animal:
Bites
Rabies from dogs, raccoon
Lyme Disease from Tick
Encephalitis from Mosquito
Contact with Environmental Sources:
Some Virus & Bacteria Live naturally in Food, Soil, & Water
Salmonella Bacteria – Undercooked Poultry, Eggs, Meat
Tetanus – caused by bacteria that live naturally in soil; enter a
person’s body through open wounds
Treating Infectious Diseases:
Bacterial Diseases:
Antibiotics
A chemical that can kill bacteria without harming a person’s cells
When you are given an antibiotic, should you take the whole prescription even
after you start feeling better?
Why or Why not?
Viral Diseases:
NO CURE using Medications
Can ONLY treat the SYMPTOMS
Ex: Flu, Chickenpox, AIDS, Hepatitis C
What is the BEST treatment for Viral Diseases?
Resting
Drinking lost of fluids
Eating well-balanced Meals
Preventing Infectious
Diseases
1. Vaccine
Substance introduced into the body to stimulate the
production of chemicals that destroy specific viruses or
bacteria
Made from dead or altered virus or bacteria
Activate the body’s natural defenses…if that virus or bacteria
ever invades your body, it is destroyed before the disease is
caused.
Common Vaccinations:
Polio, Measles, Tetanus, Chickenpox
Preventing Infectious
Diseases
2. Keep Your Body Healthy
Eat Nutritious Meals & Fluids
Enough Sleep
Exercise
Washing Hands
Do NOT share eating or drinking utensils
Store and Cook food Properly
Viruses
Tiny, nonliving particle that enters THEN
reproduces inside a LIVING cell
Multiply like other Organisms but ONLY when they
are inside a LIVING cell
Act like a Parasite in the organism
Usually destroy the cells they multiply in
Host
organism providing the energy for a virus
Parasite
Organism that lives on or in a host
Causes the host harm
Virus Shapes
1. Round
Chickenpox, West Nile
2. Rod/Tube-shaped
Ex. Rabies
3. Robotlike
Bacteriophage – virus that
infects Bacteria
Structure of Viruses
2 Basic Parts:
1. Protein Coat for Protection
Allows Virus to Attach to
Cells in the Host
“Lock and Key” – Cold
Viruses infect cells only in
the nose and throat
2. Inner Core of Genetic
Material
Instructions for making New
Viruses
How Active Viruses Multiply
1. Virus Enters the Cells
2. Virus’s genetic material “Hijacks “ Cell
function  Forces host cell to produce the
Virus’s proteins and genetic material
3. New Protein/Genetic Material forms many
new viruses (Copy Machine stuck on “Copy”)
4. Host Cell BURSTS open when Full hundreds
of new virus released
5. Host cell dies
How Hidden Viruses Multiply
1. Virus Enter the Host Cell
2. Virus’s genetic material Becomes part of the Host Cell’s
genetic material BUT does NOT take over
3. When the host cell divides, virus is also copied
4. Under certain conditions, the virus will become active & takes
over the cell functions like an Active Virus
Can be months or years after Invasion
Ex. Cold Sores activated by stress or heat
Usefulness of Viruses
Gene Therapy
Scientists add genetic material to a virus
Virus is used as a “messenger Service” to deliver
genetic material to cells that need it
Being used to treat Cystic Fibrosis
Bacteria
Single -Celled
Prokaryotes
Have ____ Nucleus
Discovered by Leeuwenhoek by accident
Looked at scrapings from his teeth with a
microscope and saw tiny, wormlike organisms
Structure of Bacteria
1. Rigid Cell Wall
Protection
2. Cell Membrane
Controls in/out
3. Cytoplasm
4. Ribosomes
Produces protein
5. Flagellum
Long, whiplike structure for
movement
Not on all
3 Shapes of Bacteria
What do Bacteria Need to Survive?
1. Food
Autotrophs
Produce own food
3. Reproduction
Asexual (1 Parent)
Binary Fission - One cell divides to
form two identical cells
Heterotroph
consume other
organism or food
made by other
organisms
2. Respiration
Breaking down food to
release energy
Sexual (2 Parents)
Conjugation – one bacterium
transfers some of its genetic
material into another through a
thin bridge
Endospores Formation
Smal, rounded, thick-wall forms
inside a bacterial cell
Allows bacteria to survive harsh
climatesl
Role of Bacteria in Nature
Oxygen Production
Food Production
Bacteria in apple cider Vinegar
Bacteria in Milk  buttermilk, yogurt, sour cream, cheese
Pasteurization
Heating food to a temperature high enough to kill most harmful
bacteria without changing the taste of food
Role of Bacteria in Nature
Environmental Recycling
Decomposers – break down large chemicals in dead organisms
Nitrogen-fixing bacteria - help convert nitrogen gas in the air to
nitrogen products plants need to grow
Environmental Cleanup
Convert poisonous chemicals in oil into harmless substances
Health and Medicine
Help in Digestion, Produce Vitamins, Prevent Harmful Bacteria
Gene Therapy of Bacteria
Manipulating Bacteria to make human Insulin
1970 - first medicine-producing Bacteria
Manipulating Bacteria to “hijack” Tumors in Cancer
patients
Fungi
Eukaryotes
Cell Walls
Heterotrophs
Reproduce Using
Spores
Fungi in Nature
Make substances to kill Bacteria
Ex. Penicillin
Fungal Skin Infections:
Athletes Foot
Ringworm (Not an actual worm)
Nail Fungus
Fungus IN the body:(in the body):
Malaria
Mosquitoes (tropical regions)
Amebic Dysentery
contaminated water supply
African Sleeping Sickness
Spread by tsetse fly
Nerves and brain swell
Parasites
organism that lives on or in a host organism
gets its food from or at the expense of its host
In human intestine  transmitted through a fecal-oral route
contaminated food or water or person-to-person contact
In human blood or tissue of humans  transmitted through
arthropod vectors
bite of a mosquito or fly
3 Lines of Immune Defense
1st Line: Natural Immunity
Natural, built-in defense system that provides nonspecific protection against pathogens.
1) physical barriers
skin, mucous membranes
2) chemical barriers
saliva, sweat ,tears, digestive enzymes
3) resident bioflora
Good microbes living on our skin and in our bodies
help block infection by disease-causing microbes
3 Lines of Immune Defense
2nd Line: Acquired Immunity
specific, long-term form of protection that
develops over time.
inflammation, fever, phagocytosis and nonspecific immune cells
Immune cells
eosinophils, basophils, neutrophils,
macrophage
3 Lines of Immune Defense
3rd Line: Acquired Immunity
Specific, long-term protection against microbes.
1) T-cells
helper and cytotoxic
2) B-cells
memory and plasma cells
3) antibodies.
Some Infectious Diseases You
Should Know
Colds
Flu
Strep Throat
Athlete’s Foot
AIDS
Colds
Viral infection in the respiratory system
Cold virus attacks the mucous
membranes of the nose and throat
Common effects of the cold
sore throat, runny nose, fever, etc.
Can it be treated with Antibiotics?
Flu
Influenza a.k.a“the flu”
a highly contagious viral disease
of the respiratory system
Symptoms:
fever, muscle aches
severe cough
lasts longer than cold
Athlete’s Foot
Fungal infection on skin of the feet
May be contracted from public
environments
Grows in warm and moist
environment usually between the
toes
Difficult to cure
AIDS
Acquired immunodeficiency
syndrome (AIDS)
Caused by human immunodeficiency
virus (HIV)
HIV attacks immune system cells
 organism is unable to fight off
other pathogens that may attack
the body
Strep Throat
Bacterial infection
Symptoms (mild or severe):
Fever
Pain
Redness
Swelling of the throat and tonsils
Disease/their causes
African Sleeping Sickness:
protist (vectored by tsete fly)
Athlete’s foot
fungus
Botulism
bacterium
Chicken Pox
virus
Hookworm
parasitic worm
Influenza
virus
Malaria
protist (vectored by mosquito)
Trichinosis
parasitic worm
Tuberculosis
bacterium
Strep Throat
bacterium
Amoebic dystentery
parastites