Notes for class 9th chapter why do we fall ill?

Notes for class 9th chapter why do we fall ill?

WHY DO WE FALL ILL

IMPORTANT POINTS TO REMEMBER :

·        Our body’s well being is dependent on the proper functioning of its cells and tissues

·        All our body parts and activities are interconnected. Hence disfunction of any body part will affect the entire body

·        When we are healthy , we are able to perform our physical, mental and social functions well. Thus our physical and social environment plays an important role in maintaining good health.

·        In addition to personal hygiene, public cleanliness, financial conditions, availability of nutritious food and social equality also influence the health of an individual.

·        Being in poor health is different from being diseased.

·        A person suffering from a disease is in a state of discomfort

·        Symptoms and signs of the disease appear as a result of disfunction of the affected body parts. These help to identify the disease that a person is suffering from.

·        Depending on their duration, diseases may be classified as acute or chronic.

·        Acute diseases last for a short time and do not cause major health effects,e.g. Common cold.

·        On the other hand chronic diseases persist for a long time and hence cause prolonged ill health, e.g. TB of lungs

·        Causes of the diseases may be immediate or contributory. E.g. the immediate cause of a person suffering from diarrhoea is the causative agent. The contributory causes could be:  lack of good nourishment, genetic difference, poverty or lack of public services

·        Diseases may be infectious or non infectious. Infectious diseases can be caused by microbes or other infectious agents (e.g. Malaria) whereas non infectious diseases have internal or non infectious causes (e.g. high blood pressure)

·        The infectious agents may be viruses, bacteria, fungi, protozoans or multicellular organisms like worms.

·        Category of infectious agents                    examples of diseases caused

                Virus                              common cold, influenza, dengue fever, AIDS 

               Bacteria                             Typhoid, cholera, tuberculosis anthrax,                                                                       

             Fungi                                      skin infections 

             protozoans                           malaria, Kala –azar 

              Worms                                 Intestinal worm infections, elephantiasis  

·        The type of treatment of the disease depends upon he category of the infectious agent.

·        Many infectious diseases are called communicable diseases since they can spread from one person to another.

·        Communicable disease can spread through air,water,food,sexual contact or vectors.

·        The droplets released during coughing and sneezing of an infected person can spread air borne diseases like common cold,pneumonia,tuberculosis etc.

·        Air borne diseases spread quickly in overcrowded and poorly ventilated  living conditions

·        Water borne diseases like cholera spread when drinking water gets contaminated with infectious agents

·        Sexual contact causes the spread the diseases like AIDS and syphilis from the infected person to a healthy person. AIDS virus can also spread through blood transfusion, use of infected needles or during pregnancy and breast feeding by an infected mother.

·        Vectors are intermediate animals causing the spread of disease causing agents from an infected person to a healthy person. E.g. female mosquitoes transmit many diseases like malaria when they feed on the blood of animals and humans

·        On entering the body, the infectious agents reach their specific target organs. In certain cases the target organ is related to their point of entry. For example- Typhoid causing bacteria enter through mouth and reside in gut lining.

·        In other instances, the target organ of the microbe has no relation to their point of entry. For example- HIV enters through the sexual organs but spreads to all the lymph nodes.

·        The symptoms of a disease depend upon the target organ infected by the microbese.g. cough and breathing problems are seen when lungs are infected. So based upon the signs and symptoms of the diseases we can get an idea of the target organ of the microbe.

·        The AIDS causing virus destroys the functioning of the immune system, cue to which the body becomes unable to fight even minor infections. Ultimately the patient succumbs to such infections

·        The severity of the disease depends upon the number of infectious agents present in the body.

·        The infectious disease can be treated in two ways: (1) reduce the symptoms of the disease  (2) kill the infectious agent causing the disease.

·        The approach of treatment of an infectious disease has three drawbacks: i) recovery of the patient may not be complete in certain cases                              ii) treatment requires time , hence the patient suffers from the disease may be bed ridden.                                                                                                            (iii) the patient serves as the source of spread of infection to others.

·        It is desirable to prevent the disease than to treat it completely

·        There are general and specific ways of preventing diseases

·        Infectious disease can be generally prevented by public health hygiene methods, which aim to reduce exposure to infectious microbes. Public hygiene measures include providing safe drinking water, clean environments and adequate spacious conditions for living.

·        Another general method of preventing infectious disease requires the sufficient nad balanced diet for the proper functioning of immune system

·        The principle of immunization is based on the memory of the immune system. On subsequent encounters with the same or related microbe, the response of the immune system multiply greatly, leading to quick elimination of the infection.

·        During vaccination, a vaccine (containing dead or weakend pathogen) is introduced into the body to fool the immune system into remembering the particular infection. Hence the body does not suffer when the actual microbes or pathogens make an entry in the body.

·        Nowadays vaccines preventimg many infectious diseases like tetanus, polio and measles etc, are used extensively especially in child health immunization programmes

IMPORTANT DEFINITIONS

HEALTH:  A state of being well enough to function well physically, mentally and socially.

DISEASE : Lack of feeling of ease due to impairment of health or a condition of abnormal functioning.

ACUTE DISEASE : disease lasting for a short period of time

CHRONIC DISEASE : Disease lasting for a long time, even as much as a life time

VECTORS : The intermediate aimal causing the spread of infecting agents from a sick person to another potential host

INFECTIOUS DISEASE : Disease where microbes are the immediate cause

COMMUNICABLE DISEASE : A disease capable of being transmitted from an infected person to healthy person

IMMEDIATE CAUSE OF DISEASE  : The cause which immediately kindles a disease into action.

CONTRIBUTORY CAUSE : A cause or condition whose presence makes it more probable that a particular disorder will occur, but that cause is neither necessary nor sufficient for the occurrence of the disease

ANTIBIOTICS : A substance that destroys or prevents the growth of bacteria or other microorganisms

IMMUNISATION : The process of inducing immunity by administering a vaccine to allow the immune system to prevent infection or illness when it subsequent encounters the infectious agent

VACCINE : A preparation of a weakend or killed pathogen that introduced in the body to stimulates the immune system to fight against the pathogen.

PATHOGEN: Any disease causing agent like bacteria. Virus or other micro organisms.

TEXT BOOK QUESTIONS

Q1 State any two conditions essential for good health.

A1 a) complete physical fitnessi.e. free from disease

       b) perfect mental and social being

Q2 State any two conditions essential for being free from disease.

A2 a) hygienic living condition and personal hygiene

       b) balanced diet, clean drinking water, physical exercise

Q3 Are the answers to the above questions the same or different? Why?

A3 Answers to the above questions are different, as health s a state of person’s physical, mental and social well being and disease is the state of discomfort of the body.

Q4 List any three reasons why you would think that you are sick and ought to se a doctor. If only one of these symptoms were present would you still go to doctor? Why or why not?

A4  a) The three symptoms to feel sick are cough, cold and fever. These symptoms may be due to infections. For proper diagnosis and treatment one should go to a qualified doctor.

       b) Even if only one of these symptoms is present, it is better to go to a doctor for proper treatment and to avoid further complications

Q 5 in which of the following cases do you think the long term effects on your health are likely to be the most unpleasant and why?

a)     If you get jaundice   b) if you get lice  c) if you get acne

A 5 The correct answer is Jaundice. It is a severe chronic disease. It takes several days for the patient to recover. It is a viral infection. In this the liver is infected and process of digestion is affected.

Q6 why are we generally advised to take bland and nourishing food when we are sick?

A 6 a) provide nourishment to body to recover from weakness

b)    Strength our body’s immune system

Q7 What are the different means by which infectious diseases spread?

A 7 a) through air or by droplet infection  e.g. cold

b)by contaminated water and food  e.g. cholera

 c) by vector e.g. malaria by the bite of female Anopheles mosquito or rabies by dog bite.

d) by direct contact e.g. AIDS and syphilis

        Q8 What precautions can you take in your schoolto reduce the incidence of infectious diseases?

       A 8 1) overall cleanliness of the surroundings In the school

                2) regular physical exercise

                3) hygienic eatables/ meals should be provided in school canteen

                4) supply of clean drinking water should be ensured.

                 5) children should be taught to wash hand before eating

                6) regular medical checkup should be there.

        Q 9 What is immunization?

        A 9 development of immunity against pathogen through vaccination is called immunization

        Q 10 What are the immunization programmes available at the nearest health centre in your locality? Which of these diseases are a major problem in your area

  A 10

Vaccines	Given against	Age group
Oral Polio Vaccine BCG Hepatitis B	Polio Tuberculosis Hepatitis	0-5 years All grown up children All children to protect them from jaundice

  

Q11 How many times did you fall ill in the last one year? What were the illness?

a)     Think of one change you can make in your habits in order to avoid any/ most of the above illnesses

b)    Think of one change you would like to have in your surroundings in order to avoid ay/most of the above illnesses.

A 11 I suffered from cold and cough twice  or any diseases

a)     Change in habits: I should avoid the company of persons suffering from cold and cough and not eating uncovered food. I will war clothes suitable to protect from mosquito bites.

b)    Change in surroundings: I will try to improve sanitary conditions in the surroundings I will try to not allowing water to collect near the houses to avoid mosquito breeding

Q12 A doctor /nurse/ health worker is exposed to more sick people than others in the community. Find out how can she/he avoid getting sick herself/ himself.

A 12 a) using disposable gloves, needles and syringes

            b)using sterilized instruments, steam washed clothes and aprons etc.

            c)vaccination against common diseases.

Q13 conduct a survey………. To bring down the incidence of these diseases

A 13 the three most common diseases in the area are diarrhea,malaria and typhoid. These diseases are spread through unhygienic surroundings. Three steps that could be taken by local authoritiesare: proper cleaning of garbage and regular cleaning of roads   2) spraying of insecticides   3) providing clean drinking water.

Q14 A baby is not able-----------------------------------what is the sickness?

A 14 in order to find out if the baby is sick, we can take baby’s temperature with the help of thermometer and observe if baby has symptoms like: running nose and loose motion ; cough and cold ; excessive crying ; not taking proper diet.

B) to find the sickness, the baby needs to be taken to doctor. The doctor will be able to diagnose either by his observations or by getting some laboratory tests done.

Q15 Under which--------------someone suffering from chicken pox

A 15 The correct answer is (c) because a four day fast will make her weak and she will have reduced immunity which will give her more chances of picking up chicken pox

Q16 under which------------your friend suffering from measles.

A 16 The correct answer is (c) because measles is an infectious disease, which spreads through nasal or throat discharge and contact. Visiting such a friend is likely to pass on the infection, if we have not been vaccinated.

We are likely to fall sick under condition (b) because while travelling for two days we have been in contact with many people. It is possible that some co-passengers might be suffering from one or other infectious diseases.

EXTRA QUESTIONS

Q 1 Give the expanded form of AIDS , WHO, HIV, SARS

A 1 AIDS –Acquired Immuno Deficiency syndrome

          WHO- World Health Organisation

                 HIV-Human Immunodeficiency Virus

                 SARS- Severe Acute Respiratory Syndrome

Q2 What are body’s defenses against diseases?

A 2 skin, mucus, hair,sweat, tears , HCl in stomach, white blood cells are a few body defenses against diseases

Q3 What is the meaning of good health for a dancer and for a musician?

A3 Good health for a dancer may mean being able to stretch his/her body into difficult or graceful position. On the other hand good health for a musician may mean having enough breathing capacity in his/ her lungs to control the notes.

 Q4 Why are signs of the disease more important than symptoms?

A 4 signs of the disease are more important than symptoms because symptoms do not specify the disease but through signs disease can easily be identified.

Q5 What is the major drawbacks of principle of treatment?

A 5 Major drawback of principle of treatment is that till the person is not completely cured he acts as a soursce of infection for others

Q6 AIDS is a fatal disease, explain why?

A 6 because immune system of the body get highly weakened and body suffers from severe infections repeatedly

Q7 Making anti viral drugs is harder than making anti bacterial medicines?

A 7 Biochemical pathways of virus are different from bacteria. Virus do not have life process but bacteria does. Virus have no biochemical mechanisms of their own. They enter our cells and use our machinery for their life processes.

Q8 Penicillin is not effective against common cold. Why?

A8 Because cold is a viral disease and antibiotics are not effective against viral diseases.

Q9 which disease is more harmful chronic or acute and why?

A9  Chronic as it has drastic long term effects on people’s health

Q10 Write any five causes of diseases with examples.

A 10 Causes of diseases:  1) Biological agents: bacteria, virus, protozoa

2) Nutrient agents: deficiency of proteins, minerals, vitamins

3) Chemical agents: pollutants, pollens

4) physical agents: temperature, humidity , radiations

5) Mechanical agents: mechanical forces which results in injury . sprain

Q 11 Explain giving reasons:

a)     Balanced diet is necessary for maintaining healthy body

b)    Health of an organisms depends upon the surrounding environmental conditions

c)     Our surrounding area should be free of stagnant water

d)    Social harmony and good economic conditions are necessary for good health

A11 a) Food is necessary for the growth and development of the body. Balanced diet provides raw material and energy in appropriate amount needed for the production of substances like proteins,carbohydrates, fats, minerals etc. which in turn are essential for the proper growth and functioning of the healthy body

b)Health is a state of being well enough to function well physically, mentally and socially and these conditions depend upon the surroundings environmental conditions e.g. if there is an unhygienic condition in surrounding area, it is likely we might get infected or diseased.

c) this is so because many water borne diseases and insect vectors flourish in stagnant water which causes diseases in human beings

d) human beings live in societies which determines the social and physical environment and hence both are to be kept in harmony.

For better living conditions lot of money is required. We need good food for healthy body and for this we have to earn money. For the treatment of the diseases also, one has to be in good economic conditions.