Question Bank Aids to Health

Transcription

1 Aids to Health 1. Name the following : (i) The antibiotic which was first discovered. (ii) The scientist who discovered vaccination. (iii) An immunological preparation of blood containing antibodies and antitoxins against specific diseases. (iv) Wild animal s reservoir of rabies virus. (v) A chemical substance prepared from the microorganism and used against them. (vi) The bactericidal enzyme present in tears and saliva. (vii) The organisation that suggests quarantine measures to prevent spread of disease. (viii) One combined vaccine given to babies which helps build immunity against three common diseases. Ans. (i) Penicillin (ii) Edward Jenner (iii) Serum (iv) Wolf, Jackal, Fox, Bat (v) Antibiotics (vi) Lysozyme (vii) WHO (viii) DPT vaccine. 1

2 2. Fill in the blanks. (i) is the hypersensitivity of the body to certain substances. (ii) cells release antibodies in the blood cells. (iii) The organisation which provides relief to victims of any national calamity is the. (iv) A condition of the body or a part of it in which its functions are disturbed is called. (v) A collection of dead cells and body fluids is known as. (vi) The resistance of our body against a disease is termed as. Ans. (i) Allergy (ii) Plasma (iii) Red Cross (iv) Disease (v) Pus (vi) Immunity 3. Mention whether the following statements are true or false. If false, rewrite the sentence by changing the letters printed in bold face. (i) The WHO procures and provides blood to the victims of war. (ii) Phenol is an antiseptic. (iii) AIDS stands for Acquired Immune Destruction syndrome. (vi) Alexander Flemming discovered Sulphonamide. (v) Vaccines provide active immunity to the body. 2

3 Ans. (i) False(Red Cross) (ii) False (disinfectant) (iii) False (Deficiency) (iv) False (Penicillin) (v) True. 4. Define the following: (i) Vaccine (iii) Antiserum (v) Phagocytes (vii) Antigens (ii) Immunity (iv) Antibodies (vi) Toxins (viii) Disease (ix) Allergy (x) Non-communicable diseases. Ans. (i) Vaccine : A germ culture, producing in an animal to stimulate an immune reaction and thus resistance to a particular disease (or disease-causing microorganism). (ii) Immunity : Ability of animal or plant to resist infection by parasites and effects of other harmful agents. (iii) Antiserum : Serum containing antibody with affinity for a specific antigen. (iv) Antibodies : These are a group of glycoproteins produced in the blood in response to antigens produced by the pathogen. (v) Phagocytes : Cells which can ingest particles from their surroundings. For example, WBC act as phagocytes as they engulf disease-causing pathogens which gain entry into the bloodstream. 3

4 (vi) Toxins : Any poisonous substance produced by an organism commonly injurious to the host. (vii) Antigen : Any substance that can be recognised by an already induced immune response and initiates the production of antibody. (viii) Disease : It is an abnormal condition of an organism or part of the body, as a result of infection, weakness or stress that disturbs the normal physiological functioning of an organism. (ix) Allergies : Hypersensitivity of the body to certain foreign substances is known as allergy. The allergy-causing agents are called allergens. Examples of allergies are : Hay fever, asthma and nettle rash. (x) Non-communicable diseases : Acquired diseases which are non-infectious, that is those restricted to the persons suffering from it, are known as noncommunicable diseases. They are of four types (a) Degenerative diseases, e.g., cataract, arteriosclerosis, (b) Cancer; (c) Allergies; (d) Deficiency diseases, e.g., Beri-beri, Kwashiorkor. 5. Differentiate between : (i) Antibody and Antigen (ii) Vaccine and Serum (iii) Inherited immunity and Acquired immunity. (iv) Antiseptics and Disinfectants (v) Active immunity and Passive immunity. 4

5 Ans. (i) Antibody These are substances produced by organisms in response to infection. These are plasma proteins. (ii) Vaccine It consists of dead or weakened bacteria or virus that stimulate the production of antibodies by the blood. (iii) Inherited Immunity It is due to antibodies which the organisms inherit from their parents. (iv) Antiseptics These are mild chemical substances which destroy bacteria and prevent their further growth. These are used locally in contact of body tissues. Example : Iodine, benzoic acid. Antigen These are foreign molecules which when introduced into the body stimulate the production of antibodies. These may be proteins or polysacharides. Serum It consists of antibodies that have been produced in the body of another person or animal who has gained immunity against the disease and then injecting it into the patient. Acquired Immunity It is acquired during the life-time of the organism. Disinfectants These are powerful chemical substances used for destroying microbes. These are not applied on body as they are corrosive in nature. Example : Formalin, DDT. 5

6 (v) Active Immunity When a person s own cells produce antibodies in response to infection or vaccination. It is harmless. It is long-lasting. Passive Immunity When the antibodies produced in other organisms are injected into a person to counteract antigens. The foreign antibodies may be killed by the antibodies produced by the body. It has a limited life span. 6. State the functions of World Health Organisation. Ans. Functions of the World Health Organisation (a) Combating diseases, especially communicable diseases and mental illnesses. (b) Issues epidemic warnings. (c) Assists countries to improve health and sanitation services. (d) Sets up health regulations for travel. (e) Promotes medical education and training. (f) Promotes research and development of international standards for pharmaceutical products. (g) Determines permissible level for air, water and noise pollution. 6

7 7. State the functions of the Red Cross. Ans. Functions of the Red Cross (a) It aims at providing social and medical care during war, and natural calamities such as famine, drought, flood, earthquake, etc. (b) It trains persons about first aid and related skills. (c) To procure and supply blood to needy victims of war and other calamities. (d) Arranges ambulance during emergencies. (e) Looks after maternal and child welfare centres. 8. Write a short note on the National Health Programmes. Ans. National Health Programmes The Government of India has undertaken projects for the eradication of common diseases such as malaria, tuberculosis, cholera and leprosy. The activities involved in each of the national programmes are outlined. (a) Malaria : Survey of malaria hit areas, control of mosquitoes by spraying insecticides in their breeding places, distributing anti-malaria drugs to victims. (b) Tuberculosis : Detection and treatment of active cases of tuberculosis in its early stages. 7

8 (c) Cholera : Controlling the spread of cholera by improving sanitation, safe drinking water, and proper disposal of sewage and garbage. Vaccination of healthy persons and immediate treatment of cholera victims through mobile medical units. (d) Leprosy : Detection of leprosy cases, their treatment and setting rehabilitation houses for lepers. Providing facility for educating and training them. 9. What does the abbreviation UNICEF stand for? Write a short note on it. Ans. United Nations International Children s Emergency Fund (UNICEF) is an agency under the UNO which aims to look after the welfare of children all over the world. It extends help in the form of funds for fighting malnutrition and other diseases among children. Supply of milk, food, clothes and other facilities in schools and communities are also a part of UNICEF s activities. 10. Fever is a natural defence mechanism. Elaborate the statement. Ans. Fever is a natural defence mechanism because it stimulates the phagocytes and inhibits the growth of micro-organisms. 8

9 11. What are antibiotics?. Ans. Antibiotics are chemicals produced by various fungi and bacteria which suppress the growth of other micro-organisms by interfering with some stage of their metabolism. For example, penicillin prevents the synthesis of certain components of the bacterial cell wall. 12. What is allergy? How do allergic reactions take place? Ans. Allergy is the hypersensitivity of the body to certain substances. Allergy occurs when the antigen and antibody reaction takes place inside the tissues. Allergens, the agents, which cause allergy are weak antigens. First exposure to the allergens does not cause allergy. It only helps in the formation of antibodies. But on second exposure, the allergens combine with the antibody bound mast cells. This complexing causes the cells to burst and release histamines, leading to inflammatory response in form of skin rashes, watering of eyes, frequent sneezing, inflammation of mucous membrane, etc. 13. How does the body fight viral infection? Ans. In case of viral infection, the body protects itself in the following ways: (i) The lymphocytes produce antibodies which cover the protein coat of virus and prevent it from attaching itself to the receptor of a cell. (ii) The lymphocytes destroy the cells that have been infected by the virus before they can reproduce. 9

10 (iii) The body produces high fever which limits the ability of the virus to reproduce. (iv) In case of cold, large amounts of mucous is formed in the nose and throat which traps the virus, which is then expelled by sneezing and blowing the nose. (v) The body produces a protein called interferon that provides protection against broad spectrum viruses. 14. What is disease? Name five types of microbes which cause human diseases. Ans. A disease is an abnormal condition of an organism or part, especially as a result of infection, inherent weakness or environmental stress, that disturbs the normal physiological functioning of the organism. The five microbes which cause infection are : Virus Chickenpox, influenza, jaundice, etc. Bacteria Cholera, tetanus, pneumonia, etc. Protozoa Malaria, amoebic dysentery, sleeping sickness. Worms Filaria, tapeworm, pinworm. 15. What are vaccines and how do they protect the body? Ans. A vaccine is a preparation of an antigen for preventive inoculation. When administered, it stimulates specific antibody formation in the body. It protects only against the disease for which it is made. 10

11 16. How does the human body protect itself from infections? Ans. The human body protects itself from infections using various mechanical and chemical barriers which are as follows: (i) Human skin is tough which prevents the entry of bacteria and viruses. (ii) Perspiration contains enzyme lysozyme that destroys the cell walls of many bacteria. (iii) Secretion of gastric juices kills the foreign bodies in the stomach. (iv) Saliva contains the enzyme lysozyme which attacks bacteria. (v) Respiratory tract is lined with mucous membrane and the nostrils have a mesh of fine hair to capture foreign particles passing through it. (vi) Antibodies are produced in the blood to combat toxic effects of parasitic micro-organisms. 17. Describe the various defence mechanisms which will come into action when you cut yourself with a kitchen knife. Ans. When we accidentally cut our hand with a knife, the body s second line of defence comes into play: (i) The blood capillaries around the injury became permeable due to the release of histamine by the lymphocytes, thus enabling the phagocytes to leak into the interstitial space and engulf the invading microbes. 11

12 (ii) The number of white blood cells count increases. Fever results, which provides defence by stimulating the phagocytes and by inhibiting the growth of micro-organisms. (iii) The body produces antibodies against the invading germs at the site of cut. 18. What is serum? How is it prepared? Ans. Serum : Serum provides immediate, though often temporary immunity. Its preparation involves the following steps: (i) The microbe is grown on culture media in the laboratory. (ii) The toxin is separated from it. (iii) The toxin is injected into the body of an animal (usually horse) in quantities sufficient to make it ill but not cause its death. (iv) After the animal recovers, it is now given a much stronger dose. This procedure is repeated until the animal can withstand doses that would otherwise kill an healthy animal. (v) Blood, which is now loaded with antibodies against the toxin, is drawn from the neck of the animal and allowed to coagulate. (vi) On coagulation, the serum which separates out from the clot is stored in sterilised bottles. 12