About the lesson WHY DO FALL ILL

1. Welcome to the world
of biology
Why do we fall ill???

2. What is Disease??
 Disease is any condition that may lead to discomfort,
distress, health problems, or death of the affected
person……….

4. TYPES OF DISEASES
 Acute disease – Some diseases last for only very
short periods of time, and these are called acute
diseases.
E.g. common cold

5. Other ailments can last for a
long time, even as much
as a lifetime, and are
called chronic diseases.
E.g. elephantiasis,
tuberculosis

6. Diseases are caused by :-
i) Pathogens like virus, bacteria,
fungi, protozoans or
worms.
ii) Poor health and under
nourishment.
iii) Malfunctioning of body parts.
iv) Environmental pollution.
v) Genetic disorders.

10. INFECTIOUS DISEASES
• Infectious agents
• Means of spread
• Organ specific & tissue specific
manifestation
• Principles of treatment
• Principles of prevention

11. Infectious agents - Organisms that
can cause disease are found in a
wide range of such categories of
classification.

13. Why is it important
that we think of these categories
of infectious agents?

14. As an example, let us take
antibiotics.
They commonly block biochemical
pathways important for bacteria. Many
bacteria, For example, make a cell-wall to
protect themselves. The antibiotic
penicillin blocks the bacterial processes
that build the cell wall. As a result, the
growing bacteria become unable to make
cell-walls, and die easily.

15. Means of spread of infectious
disease

16. Means of spread of infectious diseases :-
Infectious diseases spread from an infected person to a healthy person through
air, water, food, vectors, physical contact and sexual contact.
i) Through air :- Common cod, Tuberculosis, Pneumonia
etc.
ii) Through water :- Cholera, Amoebic dysentery etc.
iii) Through vectors :-
Mosquitoes :- Malaria, Dengue, Yellow fever etc.
Flies :- Typhoid, Tuberculosis, Diarrhea, Dysentery
etc.
iv) Through sexual contact :- Syphilis, AIDS.
AIDS virus can also spread though blood transfusion and from the mother to
her child during pregnancy and through breast feeding.

17. Organ specific & tissue specific
Manifestations
After entry of microbes in our body
where do they go?

18. Answer depends on Point of entry
:
• e.g. tuberculosis - caused by bacteria - entry
point through Nose to lungs

19. Prevention methods
of some common
diseases.

20. TYPHOID.
Proper
sanitation and
disposal of
faecal matter
prevents
infection .
TAB
vaccination
provides
immunity for 3
years .
Typhoral oral
vaccine also
prevents
typhoid.

25. Principles of treatment :-
The treatment of infectious diseases consists of two steps. They are to reduce the
effects of the disease (symptoms) and to kill the microbes which caused the
disease.
i) To reduce the effects of the disease :-
This can be done by taking medicines to bring down the effects of the disease
like fever, pain or loose motions etc. and by taking bed rest to conserve our energy.
ii) To kill the microbes :-
This can be done by taking suitable antibiotics and drugs which kills the
microbes and the disease is cured.

26. • e.g. Japanese encephalitis (brain fever) – virus-
enter through a mosquito bite infect the brain.

28. AIDS Viru

31. Providing
vaccines at right
time.

32. These small contributions
From you and me, will
Help us make a better
future

33. He who has health, has hope;
and he who has hope, has
everything.

34. Thank you for watching
this presentation
presented byS.Lakshna