Question

summery of the lesson why do we fall ill

Answer 1

Main topics covered in this part of CBSE Class 9 Science, Why Do We Fall Ill: Chapter Notes, are:

HealthDisease and its TypesCauses of diseaseAntibioticsPrinciple of TreatmentPrinciples of Prevention

Key notes for Chapter - Why Do We Fall Ill, are:

Health

Health is a state of complete physical, mental and social wellbeing.

Disease

Any disturbance in the structure or function of any organ or part of body.

It may be caused due to the attack of pathogens (virus, bacteria), lack of nutritious diet/balanced diet and lack of public health services.

Types of Disease

Diseases are basically of two types. They are:

(i) Acute Disease

The disease which lasts for only a short period of time is called Acute Disease.

For example: Influenza (Flu) , Common cold, etc.

(ii) Chronic Disease: The disease which lasts for long period of time is called Chronic Disease

For example: TB, Cancer, etc.

Difference between Acute Disease & Chronic Disease

S. No.Acute DiseaseChronic Disease 1.They are short duration diseaseThey are long lasting disease2.Patient recovers completely after the curePatient does not recover completely3.There is no loss of weight or feeling of tiredness afterwardThere is often loss of weight of feeling of tiredness4.There is short duration loss of work and efficiencyThere is a prolonged loss of work and efficiency 

Causes of Diseases: 

Causes of diseases are explained below:

Immediate and Contributory Cause

Immediate cause: The organisms that enter our body and causes disease is called immediate cause. For example, virus, bacteria, protozoa etc.Contributory cause: The secondary factors which led these organisms enter our body are called as contributory cause. For example, dirty water, contaminated food, improper ourishment, poor standard of living etc.

Infectious and Non-infectious Cause

Infectious causes: They include the agents like microbes or micro-organisms as the immediate causes which spread the disease from an infected person to a healthy person.

Non-infectious causes: The disease which does not spread by contact between infected and healthy person through air and water, is called non-infectious disease.

Infectious and Non-infectious Diseases

Infectious Diseases: The diseases which spread due to infection by micro-organisms are called infectious diseases.

When a disease causing organism enters our body it causes infection, it multiplies and grows in the body called host and micro-organisms multiplies in the host body.

For Example: Tuberculosis, tetanus, Common cold, AIDS, etc.

Non-infectious Diseases: The disease which does not spread by contact between infected and healthy person through air and water, is called non-infectious disease.

For example: Cancer, genetic abnormalities, high blood pressure, etc.

Means of Spreading Infectious Diseases:

S. No.Type of DiseaseExample1.Air born DiseasesCommon cold, influenza, measles, tuberculosis.2.Water born diseasesCholera, typhoid, hepatitis.3.Sexual DiseasesAIDS, Syphilis.4.Animal born DiseaseRabbis.

Antibiotics

These are the chemicals (medicine, drugs) that block biochemical pathways important for bacteria. They are used for diseases caused by 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.

Principles of treatment
1. To reduce the effects of the diseases

By taking medicines to bring down the effects of the disease like fever, pain, etc. 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 kills the disease causing microbes.

Principles of Prevention
1. General method:

They involve (a) Preventing exposure against microbes (b) By boosting the immune system

(a) Preventing exposure against microbes can be done in following ways:

For air-born microbes we can prevent exposure by avoiding overcrowded places. For water-borne microbes we can prevent exposure by not using contaminated water.

For vector-borne infections we can prevent exposure by providing clean environment.

(b) By boosting the immune system:

Our immune system plays an important role in fighting against the microbes that enter our body. strengthening the immune system can help in preventing many diseases. 

So, proper nourishment or healthy diet that includes all the necessary nutrients as well as vitamins and minerals is necessary for better functioning of our immune system.

2. Specific method
It involves the prevention method directed against a particular disease.

It is done by immunisation which is the process of introducing a weakened pathogen inside the body of the host to make his/her immune system to produce antibodies against that particular disease so that the next time even if the disease will strike the host’s body with full vigor, the body will be able to protect itself with the help of these antibodies.

Answer 2

Treatment and Prevention of Diseases

Have you heard the phrase, “Prevention is better than cure”? It sure is. We get sick every now and then due to many reasons. In such a case, we take medicines or visit a doctor. But prevention of diseases is possible. Yes! We can prevent falling ill by taking care of our health. But sometimes it’s too late and we can only treat a disease. So let’s learn about the treatment and prevention of diseases.

What is Health?

The World Health Organisation (WHO) gave the following definition of health in 1948. “Health is a state of complete physical, mental and social well being and not merely the absence of disease or infirmity”. The WHO definition of health recognizes three dimensions of health i.e. physical, mental and social. In 1978, another thing was included in this definition. It is the ability to lead a “Socially and economically productive life”.

It is rightly said that Health is Wealth. There are various factors which influence health. These factors lie both within the individual and also in the society in which he or she lives. The internal factors are basically the genetic make-up of an individual while external factors lie in the environment to which he/she is exposed.

Factors to Help Maintain Community Health

Personal health is a state of complete physical, mental and social well-being. Community health comprises of maintaining, improving and protecting the health of the entire community. The various factors that help in maintaining community health are:

★ Maintaining proper hygienic and sanitary conditions of the environment.

★ Providing good socio-economic conditions.

★ Providing health care services.

★ Imparting health education and promoting public awareness.

★ Providing proper facilities for preventing diseases.

Basic Conditions for Good Health

‘A sound mind in a sound body’ is an old saying and expresses the importance of good health. There are some common points that you must follow to ensure that you enjoy a good health. These include:

★ Have a balanced diet

★ Maintain personal hygiene

★ Keep your surroundings clean

★ Consume clean food and water

★ Keep your environment and air clean

★ Maintain a proper schedule of exercise and relaxation

★ Keep away from any kind of addictions like alcohol or drugs