Alternative medicine -1

Traditional medicine is largely mechanistic treating the body as a machine with separate parts to be treated separately. Alternative, or complementary, medicine treats the body holistically, dealing with the whole body in its environment.  In the past alternative methods, many of them ancient have been ignored by physicians. Today, however certain types of alternative medicine are used increasingly to complement traditional methods.

Acupressure: ancient Chinese and Japanese healing massage using fingertips pressure on pain relieving points around the body.  These pressure points lie along the meridians used in Acupuncture. Acupressure balances the flow of Qi or Chi, the energy flowing through the meridians.

Acupuncture: Treatment of illness by sticking special needles into one or more of 2000 specific points that lie along invisible channels called meridians. This ancient Chinese therapy is believed to control the flow of Qi, the energy flowing along the meridians. Used in the treatment of arthritis, allergy, back pain and many other disorders.

Alexander technique: A method used to retain the body’s movements, positions and posture during all activities including sitting or reading. The method, which must be learned from qualified teachers, is believed to encourage good mental and physical health, and resistance to stress, by promoting harmony between mind and body.

Aromatherapy:  Use of concentrated plant oils such as bergamot, eucalyptus or rosemary to treat conditions including stress, headaches and arthritis. Extracts, or essential oils, are massaged into the skin by aroma therapists; they can also be inhaled or added to baths.

Art therapy: Use of drawing and painting to encourage patients to explore and resolve deep seated fears and emotions that they find difficult to express in words. Used to treat addiction, alcoholism, anorexia and other conditions.

Immunization

While immunity is being acquired a person develops symptoms of the disease. But some infections can be prevented b allowing the body to acquire active immunity artificially. This is achieved by the introduction into the body of a vaccine made from dead or weakened micro organisms that are no longer capable of causing the disease itself. When injected into the skin or blood stream9 Or, as in the case of polio vaccine, swallowed) they stimulate B-lymphocytes to produce antibodies but no significant disease symptoms. And if, or when, the body encounters the real disease causing micro organism, it is already protected against infection because the memory cells immediately produce antibodies. Booster shots may be needed at later dates to ensure the active immunity is still effective. Vaccines are available against many formerly dangerous diseases including polio, measles and diphtheria. Immunization programmes for children have virtually eliminated most common childhood diseases, and confer immunity into adult life. But vaccination is advisable for travelers to countries where they may contract potentially fatal diseases not previously encountered.


Sometimes antibodies themselves, from external sources, are injected into the body to provide protection without stimulating the immune system. This is called artificial passive immunity and is useful in providing instant protection where a disease might kill the person before their active immune system has time to come into operation. Examples include gamma globulin, given against hepatitis A infection; am antitoxin to treat tetanus; and anti rabies injection.

Infectious And Non Infectious Diseases

 
Infectious Diseases

 Infections arise when disease causing micro organisms penetrate the body’s physical defenses such as the skin and entire bloodstream and tissues near their route of entry can be by infection of infected droplets, ingestion of contaminated food or water, entry through broken skin, skin to skin contact, injection by needle or other sharp object, sexual contact, insect bites, or by transmission from mother to fetus. In most of the case the body immune system acts to destroy the invading micro organism before it can do harm. Most disease signs and symptoms such as spots in measles- are indicators of the battle between the micro organism and the body’s immune system. In rare cases, the infection may be so virulent that kills the patient before the immune system has time to fight back. Before the 20th century infectious diseases were a major cause of deaths in the world. In developed countries today, deaths from infectious disease have been dramatically reduced, and non infectious diseases such as cancers and heart disease have taken over as major killers. This reduction has been achieved by better public health and sanitation; the use of antibiotics and other antimicrobial drugs; and the use of vaccines.

However there is no room for complacency since old diseases such as TB, malaria are again on the increase, some bacteria are now resistant to drugs; many viral conditions are untreatable and new diseases such as AIDS are appearing. Disease causing organisms include viruses, with are non living infectious agents; single celled organisms including bacteria, chlamydiae, rickettsiae, fungi and protists, and multicellular organisms such as parasitic worms. Viruses consist of genetic material surrounded by a protein coat, and cause diseases such as measles, mumps and rabies. Viruses have to invade host cells to reproduce. They lose their outer protein coat and use the host cell’s DNA to replicate their genetic materials. A protein coat is constructed around the rebuilt genetic material and newly formed viruses burst out of the host cell or exit in an envelope and invade other host cells to multiply further.

Non Infectious Diseases 

Non infectious diseases are now the major cause of death in the developed world. The reason for this is that many infectious diseases are now treatable with drugs. Also the incidence of non infectious diseases increases with age, and averaged life expectancy is increasing. Non infectious diseases include circulatory diseases including heart attacks and strokes, in which the blood vessels to the heart or brain becomes blocked; cancers diabetes mellitus, which is the body’s inability to control blood sugar levels; nervous system diseases such as motor neuron disease; respiratory system diseases digestive system diseases ; kidney diseases and allergies. On average, infectious diseases are responsible for just five deaths per 100000 of the population per year in the developed world, as compared with nearly 1000 deaths per 100000 caused by major non infectious diseases.

Immunization

While immunity is being acquired a person develops symptoms of the disease. But some infections can be prevented by allowing the body to acquire active immunity artificially. This is achieved by the introduction into the body of a vaccine made from dead or weakened microorganisms that are no longer capable of causing the disease itself. When injected into the skin or bloodstream (or as in the case of polio vaccine, swallowed) they stimulate B lymphocytes to produce antibodies but no significant disease symptoms. And if, or when, the body encounters the real disease causing microorganisms, it is already protected against infection because the memory cells immediately produce antibodies.

Booster shots may be needed at later dates to ensure that active immunity is still effective. Vaccines are available against many formerly dangerous diseases including polio, measles an d diphtheria. Immunization programmes for children have virtually eliminated most common childhood diseases, and confer immunity into adult life. But vaccination is advisable for travelers to countries where they may contract potentially fatal diseases not previously encountered. Sometimes antibodies themselves from external sources are injected into the body to provide protection without stimulating the immune system. This is called artificial passive immunity and is useful in providing instant protection where a disease might kill the person before their active immune system has time to come into operation. Examples include gamma globulin, given against hepatitis A infection; anti toxin to treat tetanus; and anti rabies injections.

Diets and Dieting!

The word diet is commonly used these days to describe an eating regime followed by someone in order for him or her to lose weight, even though in its correct usage the word simply describes what we eat each day. A diet designed for weight loss is better described as a slimming diet, and there are many of these to choose from. As the percentage over weight and obese children and adults in the western world steadily increases as a result of increased in activity and increased consumption of junk food – so new slimming diets, and books on slimming, become available in order to commercially exploit fatness. However, most of these diets are not effective because they fail to promote long term weight loss and in fact may well cause the slimmer to end up fatter and heavier than when they started the diet. Being overweight will of course affect an individual’s health and reducing body weight will help to reduce those health risks. But to be healthy, a diet designed to reduce body weight needs to be in tune with the body’s physiology.

 An effective diet should promote the loss of fatty or adipose tissue from the body so that its overall fat content is reduced. To do this successfully, the dieter should eat a well balanced high carbohydrate, high fiber low fat diet with energy content of between 1200 and 1500 calories per day, combining this with regular exercise. This should cause a weight loss of 0.45 to 0.95 KG per week, that weight loss being mainly in the form of fat. At the same time, exercise will build up muscle tissue which pound for pound consumes far more energy than fat does as well as increasing metabolic rate, the rate at which the body burns carbohydrates and fat to release energy. Once the desired weight has been reached – and the body fat content has been reduced to within safe limits- then the dieter can gradually increase his or her calorie consumption while maintain the same balance of foods in order to keep at the weight for life.

Other sliming diets put the body in a defensive stance. Because its calorie intake has been severely reduced the body reduces its metabolic rate to conserve its fat energy reserves and actually burns lean muscle tissues in order to provide energy. When the diet stops the body diverts as much spare food energy as possible to build up its fat reserves in case another calorie famine happens and in consequence the diet regains lost weight and ends with more fat than before

A Healthy Diet

The food that we eat provides us with the energy to power all our body activities, the materials for the growth and repair of body tissues, and the vital chemicals essential for the metabolic reactions that take place in all cells. To be healthy, a diet should:

Consist of a wide variety of natural foods that provide a balance of carbohydrates, fats,, proteins, vitamins, minerals and fibre.

 Supply the body with sufficient energy to meets its needs;

Include only low levels of foods, such as those containing saturated fats, that increase the risk of developing diet related diseases, for instance coronary artery disease.

 Each person has a certain requirement for energy, depending on their age and the amount of activity (or other forms of energy consumption, such as breastfeeding) involved in their daily life. Energy is derived from energy rich foods such as carbohydrates and, to lesser extent, fat. A diet that results in taking in more energy than the body requires in those conditions leads to obesity, while insufficient energy intakes leads to weight loss.

Vitamins and Minerals

     Vitamins and minerals are substances required in small amounts, that essential for the normal, healthy functioning of the body normal growth and development, energy productions, body maintenance, and general well being and vitality.

       Vitamins are a diverse group of organic substances that cannot be manufactured by the body – except for the vitamin D (which is produced in the skin when it is exposed to sunlight) and niacin (made in the body from the amino acid tryptophan) – and must, therefore, be obtained from food. Absence of one or more vitamins from the diet will, in time, lead to well defined deficiency diseases such as scurvy, beriberi or ostemalacia. The 13 major vitamins, each of which is found in many different foods, are divided into two groups. Fat soluble vitamins- A,D,E, and K – are found in fat or oil containing foods, and are stored in the liver, so that daily intake of these vitamins is not really essential. In fact, excessive consumption of fat soluble vitamins, usually by taking too many vitamins tablets, can be harmful. Deficiency of fat soluble vitamins is usually caused by disorders that stop the intestine absorbing fat efficiently. Water soluble vitamins- the B complex vitamins and vitamin C are not stored in the body (apart from vitamin B 12). To avoid deficiency, therefore, food containing water soluble vitamins should be eaten each day to keep supplies “topped up”. Because water soluble vitamins are destroyed by prolonged cooking, processing and storage, fresh or lightly cooked foods make the best sources.

     Minerals are simple chemical elements that cannot be made by the body but must be present in the diet o maintain good health. There are 20 minerals known to be essential in small amounts, in addition to carbon, oxygen, hydrogen and nitrogen, which are needed in large amounts to construct the body’s framework. Some, including calcium phosphorous, potassium, sulfur, sodium magnesium and chlorine and some traces of minerals such as iron cobalt copper zinc molybdenum iodine and selenium are also important for mammals.

Sleep and Sleep Disorders

    Sleep occupies around one third of a person’s life, although the hours we sleep decrease as we age. A one year child sleeps for about for about 14 hours each day, while a five year old needs around 12 hours. About 90 percent of adults sleep for six to nine hours per night, with most people sleeping 7.5 hours to 8 hours. Less than 6 hours sleep at night generally leads to daytime sleepiness. Elderly people tend to sleep less at night but doze during the day.

    Dreams are the result of mental activity during REM sleep. They are believed to represent the processing of all the thoughts and stimuli that have occurred to a person during the day. They may also form part of the process whereby short term memories are assimilated into long term memory storage. Many psychiatrists believe that dream analysis can reveal emotional conflicts.

      Sleep disorders can disrupt normal daytime functioning or cause sleepiness. Insomnia: Difficulty in falling, or staying, asleep. Around 30 percent of adults suffer from insomnia at some time in their lives. The main cause is stress, although causes include lack of exercise and misuse of drugs. Research indicates that insomniacs actually sleep more than they think but wake more often than normal. Remedies includes reducing stress levels; taking more exercise; developing a regular sleeping routine; and avoiding coffee late at night. Sleep inducing drugs are only prescribed if these remedies fail. Jet lag is a disruption of normal body rhythms caused by long distance flying across. Sleepwalking, sleep paralysis, Sleep deprivation, Sleep apnea, Night terror, Nightmares, Narcolepsy are some of the sleep disorders.

World conservation strategy

Plants and animals are unaware of Political boundaries conservation must be based on worldwide strategies. In 1980 the World Conservation Strategy was launched by IUCN (International Union for Conservation of Nature and Natural Resources), WWF (World Wildlife Fund) and UNEP (United Nations Environment Programme). It said that conservation of three factors was needed: 1. Life support cycles, water, soil and air; 2. Species of plants and animals; 3. Genetic diversity. This document became the basis of conservation policies in over 50 countries.

In 1991 IUCN, WWF and UNEP launched caring for the Earth, an updated policy document setting targets and suggesting some methods of approach. IN 1992 the Earth Summit in Rio was attended by many heads of governments, who pledged to implement much of caring for the Earth, its strategies were largely embodied in the Biodiversity Convention ( Although it was not signed by USA). Many of those good intentions have since been watered down or bogged down, but the idea survives and a number are gradually being implemented with a world system of biosphere reserves and heritage sites.

Coral reefs and Mangrove Swamps

Coral reefs are found where the average annual temperature of the sea does not drop below 21.C. they are the richest of marine environments, estimated to contain one third of the world’s fish species and up to 500,000 animal species in all. Reef corals can only thrive in shallow water, so are often close to land, and therefore at special risk from human activities. Dangers include pollution; dredging and removal for construction purposes; damage by collection of coral and other invertebrates as tourist trophies; and collection of fish for the aquarist trade, which has already wiped out some species of colourful reef fish.

 Mangrove swamps occur in tropical regions where soft sediments are covered with sea water. In cooler areas salt marshes take their place. Both types of environment are rich in species. Mangrove swamps are the nurseries for many kinds of open water tropical fish; salt marshes are feeding grounds for the worlds migrating waders and water fowl. Yet both environments are regarded with disfavor by the majority of human kind and there has been greater destruction of mangrove swamps than of any other habitat type. Currently about 165, 000Km2 of mangrove forest remain, but almost all are under threat largely from pollution, which in some cases causes harmful mutations, and from expansion of farming.

Wetlands

The wetland ecosystem- rivers, streams, lakes, ponds and swamps- is under threat. Currently covering about 6 percent of the Earth’s surface, wetlands are shrinking rapidly. Destruction of wetlands may seem to bring nothing but benefit. Draining a marsh creates fertile land for cultivations and reduces breeding areas for insects such as mosquitoes. Damming a river provides a water supply, and may mean a source of power as well.
But many changes to water system carry seeds of disaster.
 The Aswan Dam on the upper Nile, completed in 1963 and fully effective by the 1970s, was meant to regulate the river’s flow and provide hydro electric power. However, the traditional fertility of the Nile valley was dependent on over 100 million tones of silt deposited annually as the river flooded. The silt is now silting up the artificial Lake Nasser, forcing farmers downstream to rely on fertilizers, and robbing local brick makers of raw materials; around 35 percent of Egypt’s cultivated land is suffering from salination. Deprived of nutrients, the fish stocks of the eastern Mediterranean are declining while the Nile delta is being eroded steadily. Schistosomiasis is a disease common in newly irrigated areas, has spread explosively, causing debilitation and death; in 1990 between five and six million people were affected.
Surviving wetlands are often badly damaged: by engineering schemes; by eutrophication, when nutrients flow off the land causing huge growths of weeds that over whelm other plant life; by pollution from sewage or toxic industrial waste; or by thermal pollution from water used for cooling.

Habitats in Danger

Habitat destruction is the greatest threat to plant and animal species worldwide. In some cases, such as felling of tropical forests or draining of wetlands, damage is frequently done under the impression that the environment is being improved for human food production or habitation. In others, lack of understanding of the importance of particular environment in the life cycles of certain species has led to their downfall. Drainage of mangrove swamps, nurseries for many kinds of fish, falls in to this category.

Sometimes wetland areas are seen as places where disease carrying insects breed, so they are drained without thought of their importance to the environment as a whole. Forests are felled because of the value of the wood they contain, regardless of the fact that they act as a water holding system, without which rivers may run faster in rainy seasons, causing soil erosion in their upper reaches and problems of silting as the river approaches the sea.

 In some areas, even nonessential human demand is regarded as paramount –for example, the breeding beaches of marine turtles in many parts of the world have been sacrificed to holiday homes and hotels, used by a comparatively small number of wealthy visitors. Although experience should show that environmental change often has far reaching effects not foreseen in the early stages of change, mankind seems to be at many instances incapable of learning.

Extinction of Plants

Plant extinctions have followed the same pattern as animal extinctions. Destruction of environment, particularly on isolated islands, has led to the most dramatic losses. On Hawaii, for example, about 300 plant species have become extinct within the last 300 years. On St. Helena, only 20 of over 100 species of native plants survive and of these 15 are in danger of extinction. It is said that of Barbados all native trees were felled within 40 years of the island’s discovery by European.
Just as an animal species may depend on one plant for survival, the reverses may also be true. For instant, the dodo tree, once abundant in Mauritius, has been reduced to 13 very aged trees since the extinction of the dodo, which ate and dispersed its seeds.
Commercially valuable plants have often been exterminated by over exploitation. Mauritius ebony and Sanfernandez sandalwood are both extinct, examples of felling without provision for regrowth. The wine palm of Dominica, tapped to make spirit in a way that killed it, became extinct in the 1920s.
Habitat destruction is the greatest threat to plant and animal species worldwide. In some cases, such as felling of tropical forests or draining of wetlands, damage is frequently done under the impression that the environment is being improved for human food production or habitation. In others, lack of understanding of the importance of particular environment in the life cycles of certain species has led to their downfall. Drainage of mangrove swamps, nurseries for many kinds of fish.

Domesticated Animals

When an animal species is domesticated, it is changed in many ways from its wild ancestors. it may become bigger, stronger and more fecund than the ancestral form. Remaining wild animals are regarded as weeds to be intractable and may have characteristics that have been bred out over generations.

Camel: Date of first domestication uncertain, perhaps by 4000BC. Dromedary, one humped camel unknown as a wild animal. Bactrian camels endangered.

Cat: First domesticated before 1500 BC. Now greatly reduced in the wild.

Cow: Firstly domesticated about 400BC. The wild ancestor, the aurochs, became extinct before 1630.

Donkey: First domesticated about 3500BC. Now extinct over almost all of its former range. Remaining wild asses endangered.

Goat: First domesticated about 7000BC. Now found only in the most remote mountainous areas.

Horse: First domesticated about 3500 BC. Now extinct in the wild: several hundred przewalski’s horses survive in zoos round the world.
Pig: First domesticated about 7000BC. Almost, the only domestic animal that still survives in significant number in the wild.

Sheep: First domesticated about 8000BC. In Europe reduced to wild populations in Corsica and Sardinia. Elsewhere found in remote mountain areas.

Wolf: The first animal to be domesticated, before 10,000 BC. Once the most widespread mammal now reduced to strongholds in remote places. No longer found in most of Europe; numbered in tens in those western European countries where it survives.

Domesticated animals would seem to be in the least danger of extinction. However, in a world where efficiency of production rules supreme, many domestic breeds, slower in growth or less productive in the amounts of meat or milk they provide, have disappeared in recent years. Attempts are now being made to rescue the genetic heritage they represent, for they may be of use in the development of future breeds.

Biodiversity

Each living thing is unique, different in details from all others. However, individuals may be grouped into kinds or species, which are defined as assemblies of organisms that in nature are capable of interbreeding freely but are unable to breed with any other species. The exact number of species of plants and animals is unknown, for more are being discovered all the time. To date, over a million of species of animals and a quarter of a million species of plants have been described and named. Estimates vary as to how many remain to be recognized. A few researchers suggest up to 30 million, but most biologists believe that around eight million are so far unknown. The figure may be raised by recent findings that the deep sea, hitherto thought to be sparsely in habited, could contain up to two million new species.

This huge diversity of living things has come about because each within its environment occupies a niche that is different from all of the others. The differences may often be slight but no two creatures or plants can make identical demands on their habitat. Recent work has shown that in a species rich environment the use of the Sun’s energy is more efficient than in a species poor habitat. Within an environment, species are largely interdependent. If a species should be lost rapidly, there is likely to be a knock on effect as other plants and animals feel the consequences. The pattern of life in the whole are is changed and probably impoverished.

Air-borne and acquatic mammals

Most mammals are firmly based on the ground or in the trees. Some can glide from tree to tree on outstretched flaps of skin, but only the bats can really fly. Their wings are supported on long fingers and run along the side of the body to take in the back legs and tails well. They are nocturnal and find their way about by echolocation – sending out high pitched sounds and listening for the echoes coming back from nearby objects. They can pick up the echoes from flying insects which enables them to change course to catch them.
Many mammals live in water, but most have to return to land to breed. Only the whales and sea cows are fully adapted for life in the water. Their front limbs form flippers and their tails form lobe like flukes. Hind limbs are absent, apart from some skeletal remains inside the body. The animals mate and give birth in water, and the only thing that indicates a terrestrial origin is that they still breathe air.

Types of Mammals

In terms of reproductive behavior, mammals fall into three groups- the egg layers, the pouched mammals and the placentals. The egg layers or monotremes, show several reptilian features and are represented only by the platypus and the echidnas. The pouched mammals, or marsupials, are confined mainly to Australia and New Guinea. They are born at very early stage – the new born red kangaroo is about the size of a broad bean- and continue their development while feeding on milk in a pouch on the mother’s body. Placentals, which make up the vast majority of living mammals, give birth to their young at a much later stage of development. While inside the mother’s body the offspring are nourished by the placenta, through which food and oxygen pass from the mother’s blood stream to the foetal blood stream. Many placental babies are so well developed by the time of birth that they can run about almost as soon as they are born.

Man has domesticated many mammal species for both work and pleasure, and has also created many different new breeds. Small mammals, especially rodents such as mice, gerbils, hamsters and guinea pigs, make excellent pets for children. Among slightly larger animals, cats and rabbits make good pets. Dogs were the first animals to be domesticated, probably over 10,000 years. Their ancestors were almost certainly a race of small wolves that lived in Southwest Asia. There are now well over 400 recognized breeds of dogs, including a wide range of working and sporting dogs as well as the more familiar pets.

Horses were first domesticated more than 4,000 years ago, when at least two breeds of wild horses- the Tarpan and Prexewalski’s horse – roamed the steppes of central Asia. One or both of these may have contributed to the domestic horse. Many breeds of horse now exist, from tiny ponies to the great shire horses once common farm animals and now making a comeback as draught animals.

Mammals

       Mammals are generally considered to be the most advanced group of animals; this is the class that contains man and the ape. All mammals have relatively large brains and a greater capacity for learning than most other animals. Unlike that of a reptile, the lower jaw of a mammal consists of a single bone, the dentary, on each side. This of great help to paleontologists in identifying fossil skeletons. Mammals first appeared on the earth a little over 200 million years ago, the descendants of some small insect eating reptiles, but they did not come to prominence until the extinction of the dinosaurs about 65 million years ago.

        When the dinosaurs disappeared, mammals were able to investigate many different ways of life and evolve in different directions. Since then thousands of species have come and gone many of them weird experimental forms such as the shovel lipped elephant and the giant Baluchitherium. The latter looked like a cross between a rhinoceros and a giraffe and, with a weight of perhaps 30 tones, was the largest of all known land mammals. Today, however, there are only about 4,100 mammalian species. The mammal teeth vary according to the animal’s diet. Carnivores have sharp edged cheek teeth that are suitable for slicing through meat. Herbivores, in contrast, have flat grinding teeth. Rodents have chisel like front teeth.

Birds

Birds evolved from reptilian ancestors about 140 to 150 million years ago. The earliest known bird is the Archaeopteryx, several fossils of which have been found in Germany; about the size of a pigeons. Archaeopteryx had many reptilian features, including toothed jaws and lizard like tails, but it also had feathers and was undoubtedly a bird. Birds are the only animals with feathers, which clearly evolved from reptilian scales. As well as aiding birds in flight, feathers help them to maintain their bodies at a constant high temperature. Each feather has a horny shaft, a rachis and numerous branches, barbs. The barbs of the outer feathers are linked together by hooked branches, barbules. The wingtip feathers are primary or flight feathers; those nearer the body are secondary feathers.
 Modern birds have no teeth and with their front legs turned into wings, their bills or beaks have to collect and process their food. The bill of each species is admirably suited to its diet. Many birds have lost the power of flight during their evolution. The ostrich the world’s largest living bird- grew too big to fly. However, its size and fast running in short burst give it plenty of protection. Rheas in South America, emus in Australia and cassowaries in New Guinea have evolved in similar ways and have all come to look alike, although they are not closely related. Birds living on islands with no mammalian predators often became flightless. The kiwi of New Zealand is a familiar example. Some of these birds died out when man introduced cats and other mammals, and many more are now in danger of extinction. Penguins cannot fly in the air, but they use their powerful wings as flippers to fly underwater.

Fangs and Venom of Snakes

         Venomous snakes inject their venom with fangs. These are enlarged teeth – at either the front or the back of the mouth. The venom is produced in glands in the roof of the mouth. Rattle snakes and vipers have very long fangs that are folded back along the roof of the mouth when not in use. The longest fangs, up to 5cm long, belong to Africa’s gaboon viper. Snakes can swallow prey much fatter than their own bodies because they dislocate their jaws to give an enormous gape. Furthermore the ligaments stretched between bones are extremely elastic. Using their teeth like ratchets, they gradually work their jaws forward to engulf the prey. 

        Only a few venomous snakes are really dangerous to humans, but the most poisonous ones are not necessarily the most dangerous because they may be timid or not live in the places where they don’t be in the contact with the people. Many number of peoples were killed by the most dangerous snakes are primarily the Indian Cobra and saw scaled viper. Both kill thousands of people in Indian and Southeast Asia each year, although exact figures are impossible to obtain. The puff adder is probably the most dangerous of the African snakes, while the western diamond back rattlesnake kills more people than any other North American snake.