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UNIT VIII, BIOLOGY IN HUMAN WELFARE, , , , Chapter 8 Blolegy |s the youngest of the formetised alsciplines of natural, Human Health ond Disease science. Progress in physics ana chemistry proceeded much, , faster than in Biology. Applications of physics and chemistry in, Chapter? our dally life also have a higher visibility than those of biology., Strategies for Enhancement in However, twentieth century and certainly twenty-first century, Food Production hes demonstrated the utility of biological knowledge In, , furthering human welfare, be it in health sacter or agriculture., Chapter 10 The discovery of antibiotics, and synthetic plant-derived drugs,, Microbes in Kumen Welfare angesthetics have changed mecicel practice on one hand, , and human health on the other hand. Life expectancy of, human beings have dramatically changed over the years., Agricultural practices, food processing ond diagnostics have, brought socio-cultural changes in human communities. These, are briefly described in the following three chapters of this unit.
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Bom In August 1925 in Kumbakonarn in Tamil Nadu, Monkamlou Sambosivan, Swaminathan did his graduation and post-graduation in Botany from, Madras University. He worked in different capacities in large number of, Institutions In India ond abroad onc developed his expertise In genetics, ond plant breeding., , The School of Cytogenetics and Radiation Research established at the, Inclan Agriculture’ Research Institute (ARID enabled Swaminathan and his, tear to develop short-duration high-yielding varieties of ice including scented, Basmoti He is also known for the development of the concept of crop, cafeteria, crop scheduling and genetically mproving the yield and quality, , Swaminathan initiated collaboration with Norman Borlaug, which, culminated in the ‘Green Revolution’ through introduction of Mexican, M.S. SWaMINeTHAN ——Vegioties of wheat in India. This wes highly recognised and oppreciated. He, , oe 6 also the initiator of ‘Lab-ta-Land’, food security and several other, environmental programmes. He has been honoured with Padma Bhushan, ond several other prestigious awards, medals and fellowships by institutions, of excellence, , , , , , 2021-22
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CHAPTER 8, HUMAN HEALTH AND DISEASE, , 8.1 Common Diseases in, , , , Humans, a2 1 ‘ny Health, fora long time, was considered as a state of body, and mind where there was a balance of certain ‘humors’., 83 AIDS This is what early Grecks like Hippocrates as well as, 84 Caner Indian Ayurveda system of medicine asserted. It was., , thought that persons with “blackbile’ belonged to hot, personality and would have fevers. This idea was arrived, at by pure reflective thought. The discovery of blood, circulation by William Harvey using experimental method, and the demonstration of normal body temperature in, persons with blackbile using thermometer disproved the, “good humor hypothesis of health. In later years, biology, stated that mind influences, through neural system and, endocrine system, our immune system and that our, immune system maintains our health. Henee, mind and, mental state can affect our health, Of course, health is, affected by =, ( genetic disorders - deficiencies with which a child ts, born and deficiencies /defects which the child inherits, from parents from birth;, (ii) infections and, (iii) life style including food and water we take, rest and, exercise we give to our bodies, habits that we have or, lack etc,, , 8&5 Drugs and Aleohol Abuse, , 2021-22
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OLOGY, , The term health is very frequently used by everybody. How do we, define it? Health does nat simply mean ‘absence of disease’ or ‘physical, fitness’. It could be defined as a state of complete physical, mental and, soctal well-being. When people are healthy, they are more efficient at, work, This increases productivity and brings economic prosperity, Health, also increases longevity of people and reduces infant and maternal, mortality., , Balanced diet, personal hygiene and regular exercise are very important, to maintain good health. Yoga has been practised since time immemorial, to achieve physical and mental health. Awareness about diseases and, their effect on different bodily functions, vaccination {immunisation}, against infectious diseases, proper disposal of wastes. control of vectors, and maintenance of hygiene in food and water resources are necessary, for achieving good health., , When the functioning of one or more organs or systems of the body is, adversely affected, characterised by appearance of various signs and, symptoms, we say that we are nol healthy, i.c., we have a disease. Diseases, can be broadly grouped into infectious and non-infectious. Discases, which are easily transmitted from one person to another, are called, infectious diseases. Infectious diseases are very common and every, onc of us suffers from these at sometime or other. Some of the infectious, diseases like AIDS are fatal, Among non-infectious diseases, cancer is the, major cause of death, Drug and alcohol abuse also affect our health adversely,, , 8.1 Common Diseases In HuMANS, , A wide range of organisms belonging to bacteria, viruses, fungi., protozoans, helminths, ete., could cause diseases in man. Such diseasecausing organisms are called pathogens. Most parasites are thercfore, pathogens as they cause harm to the hast by living in (ar on) them, The, pathogens can enter our body by various means, multiply and interfere, with normal vital activities, resulting in morphological and functional, damage. Pathogens have to adapt to life within the environment of the, host. For example, the pathogens that enter Lhe gul must know a way of, surviving in the stomach at low pH and resisting the various digestive, enzymes. A few representative members from different groups of, pathogenic organisms are discussed here alongwith the diseases caused, by them. Preventive and control measures against these diseases in general,, are also briefly described., , Salmonella typhiis a pathogenic bacterium which causes typhoid, fever in human beings. These pathogens generally enter the small intestine., through fued and water contaminated with them and migrate Lo other, organs through blood. Sustained high fever (39° to 40°C), weakness,, stomach pain, constipation, headache and loss of appetite are some of, the common symptoms of this disease, Intestinal perforation and death, may occur in severe cases. Typhoid fever could be confirmed by, , 2021-22
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HUMAN HEALTH AND DISEASE, , Widal test : A classic case in medicine, that of Mary Mallon nicknamed, Typhoid Mary, is worth mentioning here. She was a cook by profession, and was a typhoid carrier who continued ta spread typhotd for several, years through the food she prepared., , Bacteria like Streptococcus pneurnoniae and Haemophilus influenzae, are responsible for the disease pneumonia in humans which infects the, alveoli (air filled sacs) of Uhe lungs. Asa result of the infection, the alveoli, get filled with fluid leading to severe problems in respiration. The symptoms:, of pneumonia include fever, chills, cough and headache. In severe cases,, the lips and finger nails may turn gray to bluish in colour. A healthy, person acquires the infection by inhaling the droplets/aerosols released, by an infected person or even by sharing glasses and utensils with an, infected person. Dysentery, plague, diphtheria, ete., are some of the other, bacterial diseases in man., , Many viruses also cause diseases in human beings, Rhino viruses, Tepresent one such group of viruses which cause one of the most infectious, human ailments — the common cold. They infect the nose and respiratory, passage but not the lungs, The common cold is characterised by nasal, congestion and discharge, sore throat, hoarseness. cough, headache,, liredness, etc., which usually last for 3-7 days. Droplets resulting from, cough or sneezes of an infected person are cither inhaled directly or, transmitted through contaminated objects such as pens, books, cups,, doorknobs, computer keyboard or mouse, etc., and cause infection in a, healthy person., , Some of the human diseases are caused by protazoans ton. You might, jawe heard about malaria, a disease man has been fighting since many, years. Plasmodium. a tiny protozoan is responsible for this disease. Different, species of Plasmodium (P. wax, P. malaria and P. falciparum) are, responsible for different types of malaria. Of Lhese, malignant malaria caused, by Aasmodium falcipanumnis the most serious one and can even be fatal., , Let us take a glance at the life cycle of Plasmodium (Figure 8.1)., Plasmodium enters the human body as sporozoites (infectious form), through the bite of infected female Anopheles mosquito. The parasites, initially multiply within the liver cells and then attack the red blood cells, (RBCs) resulting in their rupture. The rupture of RBCs is associated with, release ofa toxic substance, haemazain, which is responsible for the chill, and high fever recurring every Lhree to four days. When a female Anopheles, mosquito bites an infected person, these parasites enter the mosquito’s, body and undergo further development. The parasites multiply within, them to form sporozoites that are stored in their salivary glands. When, these mosquitoes bite a human, the sporozoites are introduced into his/, her body, thereby initiating the events mentioned above. It ts interesting, lo note that the malarial parasite requires two hosts — human and, mosquitoes — to complete its life cycle (Figure 8.1); the female Anopheles, mosquito is the vector (transmitting agent) loo., , 2021-22
