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