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E-CONTENT PREPARTION

FOR CLASS IX SCIENCE��CHAPTER-13 WHY DO WE FALL ILL?��PREPARED BY

SMT. DEEPANJALI JENA, PGT BIOLOGY

JNV DEOGARH

NAVODAYA VIDYALAYA SAMITI NOIDA

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Health:- State of being well.

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Factors affecting Health

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Social Determinants of Health

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1. personal health 2. community health

Conditions for good health:-
Clean environment
Personal hygiene.
Proper balanced diet.
Immunization/vaccination
Maintenance of community health:-
Proper sanitation of surrounding environment.
Health education
Maternity and child care
Prevention and control of disease
Health care services

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Community Health

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Disease

organs.

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Healthy vs Disease Free

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SYMPTOMS AND SIGNS OF DISEASES:-

Symptoms of disease are the things we feel as

being ‘wrong’. Like headache, fever, loose motion etc.

Signs of disease are what physicians will look for on the basis of the symptoms. Signs will give a little more definite indication of the presence of a particular disease.

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Causes of Diseases

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Types of Diseases based on Time Duration

characteristics	Acute disease	Chronic disease
Duration	short duration	long lasting disease
Recovery	recovers completely	does not recover completely.
Changes in body	no loss of weight or feeling of tiredness afterwards	often loss of weight, feeling of tiredness
Effect on lifestyle	short duration loss of work or efficiency	prolonged loss of work and efficiency

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Types of Diseases (spreading or not)

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Causative Agents of Infectious Diseases

Bacteria	Virus	Fungi	Protozoa	Worms
Living	Nonliving outside the host body.	Living	Living	Living
Multiply quickly in host	Multiply quickly in host	Multiply quickly in host	Multiply quickly in host	Multiply slowly in host

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Causative Agents of Infectious Diseases

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Modes of Infectious Disease Transmission

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Five – ‘F’:Prevention of Disease Transmission

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ANTIBIOTICS:-

Why to study about various infectious agents ?
For the kind of treatment that to be used .
Antibiotics
These are the chemicals (medicine, drugs) that block biochemical pathways important for bacteria.
Antibiotics do not work against viral infections as the viruses do not have their own biochemical mechanisms but depend upon that of the host.

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Antibiotic Action

Have own biochemical pathway

Do not have own biochemical pathway

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Mechanism of Antibiotic Action

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Manifestation means clear sign of pathogens in the body.

Microbes/ Pathogens	Organ where it enters	Organ effected	Means of spreading	Disease caused
Bacteria	Nose	Lungs	Air	Tuberculosis
Plasmodium	Blood	Liver and RBC	Mosquito bite	Malaria
HIV	Macrophage/WBC	Immune system	Sexual contact	AIDS

symptoms depends on:-

The tissue or organ that the microbe is infecting.

It may specific or general.

Manifestation of Diseases

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Tuberculosis

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Immunity: The disease resistance ability.

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Some microbes compromises the immune system/immunity (disease resistance power).
The immune system is activated in response to the disease and recruit cells to kill off the disease causing microbe by the process of inflammation.

Severity of disease manifestation depends on
Number of microbes in the body ( Immune system is a major factor that determines the number of microbes in the body).

Immune System

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�1. To reduce the effects of the diseases

By taking medicines and by taking complete rest to conserve the body’s energy.

2. To kill the cause of the disease

By taking suitable antibiotics and drugs which kill the disease causing microbes.

Principles of Treatment

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Why to prevent disease and how to prevent disease?

Prevention is better than cure:-

Once someone has a disease , may not recover completely.

2. Treatment take some time.

3. can serve as a source of infection for others.�

Principles of Prevention

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Prevention vs Cure

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GENERAL WAYS

SPECIFIC WAYS

Preventing exposure against microbes and boosting immune system.
avoiding overcrowded area.
Providing safe drinking water.
Providing clean environment.
Availability of sufficient and nutritious food.

Protection against a specific microbe by developing immunity to kill them.
Can be in born or acquired after birth.
By immunisation (introducing weakened pathogen in the host body to produce antibody against it.)
Vaccination: providing immunity to a healthy person by giving vaccines.( dead or weakened pathogen injected to produce antibody)