5.3 science helps people prevent and treat diseases
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SCIENCE HELPS PEOPLE PREVENT AND TREAT DISEASES.
Lesson 5.3
Introduction:Flu , influenza, chicken pox and
hepatitis are all kinds of diseases.DISEASE is a change that disturbs the
normal functioning of your body.Diseases are caused by
MICROORGANISMS .Microorganisms cant be seen by our
nacked eye.
1-So the discovery of the microscope was a great event in science. It helped scientists to detect the cause of diseases.
FIRST MICROSCOPE
secondUnderstanding diseases and
studying them helped in PREVENTION and TREATMENT of many illnesses….
SCIENCEThe effort done by many
scientists lead them reach the theory which says
“Infectious diseases are caused by germs.”
Food decay was a clear view to study the presence of germs.
GERMS could be:A- Bacteria
B- Viruses
C- Fungi
D- Protists
BACTERIADeff: are single
celled organisms that can live every where
Bacteria growing in agar an seen under microscope
BacteriaSome bacteria like that found in
the normal flora of our intestine can be helpful , it helps in certain food digestion.
Other bacteria are harmful causing diseases like : pneumonia , ear infection and strep throat.
Dividing Bacteria
In the previous centuries people used to die from diseases considered nowadays as very easy curable ones,,
Also they used to die after successful surgeries due to simple infections..
Later on doctors understood the germ theory of PASTUER which is
“Diseases are caused by GERMS”
Nowadays infections due to bacteria are treated ay ANTIBIOTICS . Which was a major turnpoint in medicine..
Other factsOther than medicines people are
getting use of bacteria in industry by producing dairy products, vinegar , and in sewage disposal to clean up organic wastes..
Biologists are also using bacteria to perform their experiments and produce certain useful proteins using the bacteria’s body and viruses them selves. eg : production of insulin for diabetic people.
VIRUSESCant be
considered as living things since it must enter living cells and get use of its DNA in order to reproduce.
Example: stomach flu and colds.
VIRUSES forms
Dividing viruses
Viruses could also infect: computers
And….. cellphones
TREATING INFECTIOUS diseases
ALEXANDER FLEMING was growing bacteria in agar plates where he saw clear area around a mold.
So by accident Fleming discovered the cure against bacterial infections which is now known as “ANTIBIOTICS’’ …
FLEMING
penicillin - YouTube.flv
SOPenicillin is a substance produced
by molds (kind of fungus) and serves as antibiotic which is a cure for bacterial infections not viral ones.
How does infectious diseases spread?Food, air and water.
Contact with animals
Person-to-person contact
Food, air and waterPathogens could be found any
where so people must take the correct precautions to prevent the spread of bacteria and viruses especially those responsible of contagious diseases..
Precautions to take::::::::::::::;
Cover your mouth when you cough or sneeze.To prevent the
spread of viruses to the surrounding air
Wash fruits and vegetables very well
Cook the meat and egg
Since high temperature kills germs
Purify the waterEither by adding
chlorine or by boiling the water or simply by using filters.
Contact with animalsAnimals’ fur, breath and saliva could carry
millions of bacteria.example:1- rabies “ a deadly central nervous system
disease” it’s a disease that inhabits the saliva of infected animals like raccoon or opossum..
The veterinarian can give your pet injections to prevent rabies.
2-worms also could pass from animals through our mouth or nose and enter to live in lour intestine.
3-fungus could cause us ringworms infection
Different types of animal contact
Person-to-person contactPeople are another area for
pathogens to pass through so whenever you touch someone a pathogen is transmitted either through skin, mouth nose eyes or cuts.
Simplest way to avoid receiving these pathogens is to wash your hands often and very well..
A daily bath and wash well your clothes.
WASHHHHHH
Some examples about pathogens and diseasesE .coli it’s a
bacteria causing E coli poisoning.
Prevention: Wash well fruits ,vegetables and cook meat.
How is E coli transmitted
giardiasisCaused by
giardia lamblia which is a protozoa, caused by contaminated water and close contact with infected people
It seems to have a smiley face
The deer tickIt a bacteria that
causes the LYME disease coming from a tick bite. Use repellents containing DEET.(it’s a yellow oil which repels ticks)
LYME disease
Noninfectious diseases are not contagious.These diseases do not spread by
pathogens, some exist at birth while others develop during life.
Therefore some are INHERETED diseases while others are LIFESTYLE diseases.
Diseases present at birthThese diseases are transmitted
from parents to their children through GENES.
Defected genes code for cells that do not function properly.
Usually genetic disorders come from recessive forms, which means the parents are normal while their kids hold the defected trait.eg: cystic fibrosis and sickle cell anemia.
RECESSIVE TRAITS
Cystic fibrosis: viscous secretion in the lungs.
Sickle cell anemia: poor oxygen supply
Huntington diseaseIts symptoms are
not immediately present after birth but at adulthood stage: it affect muscle coordination.
TALIPES or CLUB FOOTIs due to the
improper development of bones of the leg and foot. Its fixed through a surgery after birth.
Disease in later lifeEnvironmental conditions as well as our
lifestyle both play a great role in the quality of our health and life length.
so we must maintain a proper healthy life style including good nutriton,exercise and escape from harmful material , in order to avoid chronic diseases such as heart, lung diseases and cancer.
People with family histories of cancer must be highly aware of environmental conditions like tar and other chemicals that could increase their risk of initiating cancer.
Scientists continue efforts to prevent and treat diseases.Even though scientists reached a great
effort in understanding and treating diseases yet diseases are still a problem all over the world.
We have many progressive achievements
Like:Antibiotics and vaccinations BUTOn the other hand new illnesses and
viruses are appearing with no known cure
Example:AIDS :loss of
immunity and eventually death.
Nile virusTransmitted
through a mosquito bite and causes the brain inflammation.
Other problemsThe excessive use of antibiotics
to a certain type of bacteria will develop “RESISTANCE” which means that the bacteria strain is no longer affected by this drug.
This resistance is passed to the next generations.
THE END