12th Class

Regular consumption of alcohol either in low concentration (beer, wine, etc.) or in high concentration (brandy, whisky, rum, gin, Vodka, etc.) causes dependency on alcohol which is called alcoholism. The person who has become a habitual drinker is called an alcoholic. Ethyl alcohol is consumed as fermented beverages with low content of alcohol (beer, wine, toddy) and as distilled beverages with a relatively high alcohol percentage (brandy, rum, whisky, gin, vodka). This alcohol is rapidly absorbed from the wall of stomach and enters the blood stream within minutes of ingestion. In the liver alcohol is converted into a more toxic substance - acetaldehyde. The organ which is most affected by alcohol, is Liver. Intoxication begins from the first sip of drink containing alcohol but early signs are not visible. With the increase in its dose the body loses its control and, gradually, the individual loses his consciousness and in extreme more...

The individual is a part of community. Community health depends on active participation of its members you have just read how a person can be helped by the community to stay away from addictions. The mental health of an individual also depends to a large extent on the way he adjusts himself to the community and the way the community helps him adjust to stresses ad strains. The community plays a major role in the prevention and control of infectious diseases also. Health centres For community development and community health, the country has been divided (1st April, 1958) into 5000 blocks. On june 30, 1996, the rural areas of the country has 2424 Community Health Centres (each catering a population of 80,000 -120,000 having \[45\] doctors, 30 bed hospital with laboratory and X-ray facility), 21854 Primary Health Centres (each catering a population 20000 - 30000, having a medical officer, one more...

Symptoms and Control (1) Drugs : Drugs are normally used for the treatment of diseases. The prolonged use of drugs may lead to the dependence of the body on them. This is drug addiction. Some people without any medical advice, start taking drugs and soon become drug addicts. Certain drugs form habit, but some make the body completely dependent upon them. (2) Addiction : Some persons are unable to bear tensions or think themselves unable to solve the problems of life or due to certain other curious factors start drinking, smoking and taking certain narcotic drugs and feel relief and peace. Gradually this becomes their habit and they are addicted to these things. Thus addiction can be defined as a physical and mental dependence on any of the above mentioned factors and get temporary relief and feel pleasure. The common factors are : (3) Drug Addiction : The compounds used more...

There is a general feeling that if you are and not ill you are healthy. A truly healthy person is the one who has a sound body, lives in harmony with others, has the ability to face stresses and strains and holds certain moral and spiritual values. Body and mind are intimately related. Any disturbance in one has its effect on the other. Like the body, mind too can be come ill. It is estimated that 1 percent of the world population suffers from serious mental illness and 10 percent from mild mental disorders. In India, there are \[67\] million people with incapacitating mental disorders. Characters of Mentally Healthy Person If potential conflicting instinctive drives. A mentally healthy person has (1) Self respect. (2) Knowledge of one's capabilities and limits. (3) Independent personality but comfortably placed in hierarchy in work, family and society. (4) Feeling of friendship and trust for more...

Smoking of tobacco dried and cured leaves of plant ‘Nicotiana tobacum’ and N. rustica in the form of cigars, cigarettes, bides etc. is very toxic to the body. Smoke of tobacco contains about 300 compounds. The main compounds are nicotine, \[CO,\text{ }HCN,\] polycyclic aromatic hydrocarbons, certain other stimulating products etc. Nicotine in the blood stimulates the nervous system, relax the muscles, release adrenalin hormone and increase the rate of heart beats. In pregnant ladies growth of foetus decreases and loss of weight may takes place. Tobacco : The tobacco was first smoked by Red Indians in America. It then spread to European countries in the early 1600’s, and today a large part of the world population smoke tobacco, while some others chew it. Effect of Nicotine : Smoking was reported to produce a feeling of tranquility (calmness) and in some cases made people alert and active. Since in its early more...

Three types of medical devices used nowadays are implants, disposables and external prosthesis. (1) Implants      Implants are devices used for replacng a diseased organ or tissue within the body. Implants must be non-toxic and biocompatible and are used for replacing joint, arteries, heart valves, etc., and occasionally helpful in cosmetic surgery. Artificial Heart Valve (i) Artificial heart valves may be either mechanical or made of human or animal tissues. (ii) Mechanical valves are made from special biocompatible plastics, metal alloys and ceramics. (iii)  Tissue valves are taken from cadavers of pigs or made from the pericardium of animals. (iv) Mechanical valves develop tendency of clotting of blood, so the patient must have regular medication of anticoagulants. (v) Tissue valves do not require anticoagulants, but they tend to calcify, particularly in young. (2) Disposables (i) Oxygenator (a) The first open heart surgery was performed by Walton Lillehel (USA) in 1953 by more...

The energy obtained from biological sources is called bioenergy. Bioenergy is the use of biomass (organic matter) to produce electricity, transportation fuels or chemicals. Bioenergy sources include agriculture and forestry residues and the organic components of municipal and industrial wastes. Fossil fuels (coal, petroleum and natural gas) is not included under bioenergy. Only 0.2% of solar radiations reaching the earth is converted into biomass. This amount is about-10 times the energy produced from nonbiomass sources. Being a tropical country, India receives more solar radiations and therefore has high potential for biomass synthesis to meet the requirement of energy. Bioenergy is obtained from following types of biological sources: Animal energy : Animal energy is basically of two forms : (1) Human muscle power (HMP) : It is the form of animal energy, which is used throughout the world in the form of physical work by human race like farmers in the more...

Wild animal means any non-domesticated animal found wild in nature. It includes both vertebrates (fish, amphibians, reptiles, birds and mammals) and invertebrates (bees, butterflies, moths, crustaceans, etc.) the term “wild life” includes animals as well as plants, which from part of any habitat in nature. Some wild animals are so characteristic that they become symbols of their home countries. Thus, tiger is associated with India, white bear with Russia, Giant Panda with China, kangaroo with Australia, kiwi with New Zealand and springbok with South Africa. (1) Importance (Values) of Wild Life : Wild life is a source of danger to human life. It is a nuisance to a farmer because it often destroys his crops. The domestic livestock is denied grazing ground in sanctuaries and reserves for wild life. Similarly, the hunters are denied recreation by shooting wild life. Even then conservation of wild life becomes necessary and of great more...

The term 'biodiversity' refers to 'the variety and variability among living organisms and the ecological complexes in which they occur'. If you observe a patch of forest, you may find a wide variety of plant and animal life. The plant life may range form a small herb to a large tree, and animal life may vary from a tiny insect to a large mammal. Apart from plants and animals, numerous microorganisms, which cannot be seen with naked eyes also occur in the soil. This shows biological diversity or biodiversity of a forest patch. Thus, biodiversity can be defined as 'the totality of genes, species and ecosystem of a region' Biodiversity differs from place to place as each habitat has its distinct biota. However, many biologically rich and unique habitats are being destroyed, degraded and fragmented. The major factors that tend to decrease biodiversity are increasing human population, higher resource consumption more...

It may be defined as the most efficient and most beneficial utilization of the natural resources. Conservation is also defined as the rational use of the environment to provide a high quality of living for the mankind. Aim of conservation : The true aim of conservation, thus, includes. (1) To insure the preservation of a quality environment that considers aesthetic, recreational as well as product needs. (2) To insure a continuous yield of useful plants, animals and materials by establishing a balanced cycle of harvest and renewal. Living resource conservation has three specific objectives (1) To maintain the essential ecological processes and the life support system : This system has five elements (air, water, land, flora and fauna) which are interconnected, interrelated and interdependent; deterioration in one inevitably affects the other four elements. (2) To preserve the biological diversity : It includes two related concepts genetic diversity and ecological diversity. more...