Diseases of digestive system

Infection

         Infection means invasion of the body by micro-organisms. The most common sources of infection in dental practice are direct contact

With a patient's blood and saliva, flying particles of tooth or filling released during drilling. These sources of infection may enter the body through skin cuts or abrasions or the eyes, they may also be swallowed.

Even ancient people taught that body's first line of defense against infection was an intact surface, e.g. the outer of skin and the protective outer layer of mucous membrane. If infection had passed it the second line of defense started its action. It was the liquid secretion produced by the protective surfaces. The mucous membrane¹ and the salivary glands had produced saliva which neutralized some bacteria poisons and could kill some micro-organisms. Tears and sweat had a similar effect. The acidity of gastric juice killed many bacteria in food. The third line of defense is discovered now. It is immunity.

         And we also know that if these defense mechanisms fail to prevent² infection, the last line of defense is a response by the body called inflammation. The same is with dental diseases.

         Infection of the teeth causes caries; infection of the gums causes periodontal disease.

Vocabulary

infection – инфекция

invasion – ену

micro-organism –  микроа?за

saliva –  сілекей

filling- тіс пломбасы

abrasion – сырыл?ан

mucous membrane – кілегей ?абы?ы

 acidity – ?ыш?ылды?

gastric juice – ас?азан с?лі

immunity – иммунитет

fail to prevent – ?згерте алмау

caries – ??рт

      Answer the question:

1. What are the most common sources of infection?
2. How may the sources of infection enter the  body?
3. What did ancient people teach?
4. When did the second line of defense start its action?
5. What was it produced by?
6. What could saliva do?
7. What effect had tears and sweat?
8. When is the third line discovered?
9. What is the last line of defense?
10. What is the same with dental diseases
11. What does infection of the teeth cause?