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
second Understanding diseases and studying them helped in PREVENTION and TREATMENT of many illnesses….
SCIENCE The 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.
BACTERIA Deff: are single celled organisms that can live every where
Bacteria growing in agar an seenunder microscope
Bacteria Some 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.
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 facts Other 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.
VIRUSES Cant 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 could also infect:computers
TREATING INFECTIOUSdiseases 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’’ …
SO Penicillin 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 diseasesspread? Food, air and water. Contact with animals Person-to-person contact
Food, air and water Pathogens 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 youcough or sneeze. To prevent the spread of viruses to the surrounding air
Wash fruits and vegetables verywell
Since high temperature kills germs Cook the meat and egg
Purify the water Either by adding chlorine or by boiling the water or simply by using filters.
Contact with animals Animals’ 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 animalcontact
Person-to-person contact People 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.
Some examples aboutpathogens and diseases E .coli it’s a bacteria causing E coli poisoning. Prevention: Wash well fruits ,vegetables and cook meat.
How is E coli transmitted
giardiasis Caused by giardia lamblia which is a protozoa, caused by contaminated water and close contact with infected people
It seems to have a smileyface
The deer tick It a bacteria that causes the LYME disease coming from a tick bite. Use repellents containing DEET.(it’s a yellow oil which repels ticks)
Noninfectious diseases are notcontagious. 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 birth These 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.
Cystic fibrosis: viscous secretionin the lungs.
Sickle cell anemia: poor oxygensupply
Huntington disease Its symptoms are not immediately present after birth but at adulthood stage: it affect muscle coordination.
TALIPES or CLUB FOOT Is due to the improper development of bones of the leg and foot. Its fixed through a surgery after birth.
Disease in later life Environmental 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 toprevent 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 achievementsLike:Antibiotics and vaccinations BUTOn the other hand new illnesses and viruses are appearing with no known
Example: AIDS :loss of immunity and eventually death.
Nile virus Transmitted through a mosquito bite and causes the brain inflammation.
Other problems The 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.