Things that affect the human body and attack its defence systems

There are many things that affect the human body and attack its defence systems,they can be naturally occouring in the environment or self inflicted or caused by societys pollution of our planet. Below are some conditions, with the effects that they cause to the human body and its defence mechanisms. Alcohol consumption is a health issue which affects the vast majority. A great many people drink alcohol regularly. Although they may not be alcoholic in the sense of being addicted to alcohol, they neverthelesss expose themselves to health risks. The alcohol in wines, beers and spirits is a depressant of the central nervous system. Small amounts gives a sense of well-being, with a realease from anxiety. However, this is accompanied by a fall-of in performance in any activity requiring skill. It also gives a misleading sense of confidence. The drunken driver usually thinks he or she is driving very well. Even a small amount of alcohol in the blood increases our reaction time. In some people, the reaction time is doubled even when the alcohol in the blood is well below the legal limit laid down for car drivers. This can make a big differenece in the time needed for a driver to apply the brakes after seeing a hazard. Read this Ch. 22 Respiratory System Alcohol reduces inhibitations and it can lead to irresponsible behaviour such as vandalism and aggression. Alcohol causes vaso-dilation in the skin, giving sense of warmth but in fact leading to a greater loss of body heat. A concentration of 500mg of alcohol in 100 cubic cm of blood results unconsciousness. More than this will kill, by stopping the action of the breathing centre in the brain. High doses of alcohol can harm virtually every organ in humans body. Many of these effects are reversible with abstinence, others are not. (2) Esophagus. Alcohol is associated with nearly half of the cancers of the esophagus, mouth, and larynx. Peole who vomit too intensely after getting drunk can cause tears in their esophagus. Brain. Alcohol depresses the central nervous system and contracts brain tissue. It destroys brain cells – which unlike many other types of cells in the body, do not regenerate. Taken in large amounts over a long period of time, alcohol can cause serious problems with cognition and memory. Heart. Heavy drinking can cause heart disease, stroke, high blood pressure and heart failure. Even social drinkers who binge on special occasions can sometimes get bouts of irregular heartbeats. Lungs. Heavy drinkers have more pulmonary infections and can be more susceptible to pneumonia and lung collapse. As intoxicated person loses his reflexses and can't clear his airway when he vomits. Stomach contents may get sucked into the lungs, which can lead to choking or pneumonia. Liver. Liver damage often begins with a fatty liver, and may progress to alcoholic hepatitis. That may be followed by the buidup of scar tissue known as cirrhosis. Cirrhosis can change the structure of the liver and choke off blood flow. This can cause varicose veins, which can rupture, triggering catastrophic bleeding. Stomach. Alcohol irritates the stomach, and can cause gastritis, ulcers and acid reflux. Gastritis is an inflamation of the mucous membrane that lines the stomach. Erosion in that lining can cause constant oozing of blood into the stomach or, if a vessel ruptures, major bleeding. Kidneys. Alcohol is a diuretic that increases urine output. Prolonged heavy drinking can cause kidney failure. Small intestines ; pancreas. Alcohol blocks the absorption and breakdown of nutrients by damaging the cells lining the stomach and intestines, and by decreasing the amount of digestive enzymes secreted by the pancreas. The pancreas can become inflamed and leak digestive enzymes, which then attackthe pancreas itself. Reproductive system. In men, it impairs the production of sperm and testosterone, and can lead to interfility and impotance. In women, the effect can be decreased estrogen metabolism in the liver which increases the amount of estrogen circulating the body, which can contribute to menstrual irregularities and even interfility. Blood. Prolonged alcohol abuse can cause anemias and abnormal blood clotting, which results in excessive bleeding and easy bruising. It also impairs the functionof white blood cells, increasing susceptibility to infection. Joints ; muscles. Alcohol dependence can cause osteoporosis ; arthritis, and deform the joints. It can atrphy muscles and cause acute muscle pain and weakness. Skin. Alcohol causes the small blood vessels in the skin to dilate(open), which results in a rush of warm blood to the surface. This makes the skin look flushed and gives the person a false feeling of â€Å"being hot†. (13) Heavy drinking during pregnancy can lead to deformed babies. Alcohol can cross the placenta and damage the foetus. Pregnant women who take as little as one alcoholic drink a day are at risk of having babies with lower than average birth weights. These under-weight babies are more likely to become ill. All levels of drinking are thought to increase the risk of miscariage. (1) The affects of alcohol vary with different people. Alcohol is a drug and must be handled with care. Knowing its uses and abuses is just imporatnt as reading the instructions on a bottle of pills. It is basic preventive medicine to know how your body handlers alcohol, how much is safe to drink, and, finally, how your body gets rid of it. When people drink small of alcohol enters directly into bloodstream through the lining of the mouth and throat. The remaining amount of alcohol is absorbed by the stomach or intestine. At this point the alcohol is then dispersed uniformly throughout the body. Its effects are similar to ether or chloroform, affecting all part of the body controlled by the brain. The ability to make appropriate judgements and to exercise self-control is affected. Alcohol must be broken down in order to leave the system. More than 90 percent of the alcohol is oxidized in the liver and the remainder is discharged through the lungs and kidneys. It takes just as long for the experienced drinker to eliminate alcohol as it does for the inexperienced drinker. (15) Ultraviolet light is a part of the light spectrum that is invisible to the human eye. Part of sunlight is UV light, which creates warmth, light, photosynthesis in plants, and vitamin D synthesis in the body. The sun produces about three types of UV lights: UVA, UVB, UVC. The ozone layer filters out UVC. UVA, however, has a long wavelenght light, so a certain amount reaches the earth's surface. UVA is the predominant light to reach earth. UVA causes damage to cellular membranes and DNA, and has been implicated in ageing of the skin and the development of skin cancer. Scientists believe it is UVB lights that are the paramount cause of premature ageing of skin, sunburn, skin cancers and other skin problems, despite the fact that UVB lights constitute for only 1% of UV lights that reach our skin. (4) UV light is beneficial for people and essential in the production of vitamin D, which is absorbed into the bloodstream and nourishes and helps to maintain bone tissue. Also UV light activates the pigment melanin in the skin, and thereby creates a tan. Many people feel better when they have a tan, as it gives a healthy appearance. It is also used to treat several diseases, including rickets, psoriasis, eczema and jaundice. This takes place under medical supervision and the benefits of treatment versus the risk of UV light exposure are matter of clinical judgement. Ultraviolet light can be harmful to humans. Prolonged human exposure to UV light may result in acute and chronic health effects on the skin, eye and immune system. (3) Sunburn (erythema) is the best known acute effect of excessive UV light exposure. Over the longer term, UV light induces degenerative changes in the cells of the skin, fibrous tissues and blood vessels leading to premature skin ageing, photodamage and actinic keratoses. Sun-damaged skin develops a thickened epidermis. This is caused by faster cell renewal, which is part of the immediate defence mechanism of the skin. The epidermis will return to normal provided the skin is not repeatedly over- exposed. Constant exposure to sunlight causes the melanocytes to become chronically over-active, resulting areas of excessive melanin in the skin. Eventually, areas of damaged skin made up of increased numbers of melanocytes and increased melanin synthesis develop. Up to around 85% of the overall appearance of ageing makes photoageing. It is a slow process and proceeds for several decates before it becomes obvious. The degree of photoageing is determined by the skin type and by the total lifetime sun exposure. People who spend their lives almost entirely indooors show very little skin damage. The degree of damage to tissues in different regions of the body is directly propotional to the amount of sunlight received. In chronically sun-damaged skin the epidermis as a whole becomes thicker, and loses some of its undulations. This is probably because marginally more daugter cells are produced by the basal layer, and produced more quickly. The effect is that the spiny layer and the dranular layer thicken up. The speed at which cells are replaced slows down, and some of the function of skin, including controlling water loss, may become less efficient. There is less elasticity and increased fragility. Skin becomes dry, flaky and less reflective of light. As photoageing begins, the small blood capillaries in the dermis decrease in number and the remaining blood vessels become tortous and dilated. The elastic fibres degenerate, producing a thickened mass that replaces the collagen. Seriously photoaged skin is dry, deeply wrinkled, yellow and rough. It may be marked with darkly pigmented or whitish spots, which respectively show where levels of pigment are higher or lower than normal. With increasing sun damage small blood vessels in the dermis will become more obvious and will form the red, finely branching, spider-like marks (â€Å"broken veins†). These blood vessels are easily damaged, resulting in greater fragility of the skin, with the development of spots. Loss of elastic fibres around the blood vessels of the lower lips and ears – areas especially sensitive to chronic sun damage – may result in dilated veins. On the other hand, in protected skin the vessels tend not to be so dilated or damaged. As its worst, skin that has been over-exposed to the sun for many years looks like old leather. Constant exposure to UV light over many years can result in warty spots on the skin, called actinic keratoses. The appearance of actinic keratoses means that the skin has received far too much sun and could develop a skin cancer eventually. (4) There are three main types of cancer: Basal cell carcinoma is the most common form of skin cancer. The skin is formed of three layers. The deepest, the subcutaneous layer, is composed of fat and connective tissue and connects the skin to the underlying muscle. Above that is the dermis, the layer that containssweat glands, oil glands, and other structures of the skin. The third layer, on the surface is called the epidermis; it is there that most skin cancers arise. Basal cell carcinomas arise in the lowest of the epidermis, the basal cell layer. This type of cancer can have many different appearances: a red patch or irritated area; a small, pink pearly bump, a white or yellow scar-like area; a smooth growth with a dent in the center, or an open sore that bleeds or oozes. Basal cell carcinomas rarely spread throughout the body and death from them very rare; however, because they often occur on the face, their locally destructive effects can result in serious cosmetic deformity if not diagnosed and treated early. Squamous cell carcinoma arise from the upper levels of the epidermis, usually on places that have been exposed to the sun. Squamous cell carcinomas are most commonly found on the ears, the face, and the mouth. This type of skin cancer often arises from a precancerous lesion known as an actinic keratosis, a type of lesion that appears as a rough, flat pink spot. If the lesion becomes cancerous, it's usually raised above the normal skin surface and is firmer to the touch. Squamous cell tumour tend to be more aggresive than basal cell tumours, and are slightly more likely to spread to other parts of the body. Melanoma, the most serious form of cancer, is not as common as the other two major types of skin cancer (basal cell and squamous cell cardinomas). Melanoma begins in melanocytes, the cells in the epidermal layer of the skin that produce the pigment melanin. Melanin in normal melanocytes produces â€Å"tan† skin as a response to damage from UV light. Melanoma can arise by several routes. Sometimes it arises directly from a melanocyte. Sometimes, the melanocyte first turns into a normal mole or irregular mole, and then becomes cancerous. Melanocytes can also be found in the eye and internal organs, where they also become cancerous on occasion. Melanomas are cancerous, but the large majority do not spread right away. Many begins as a â€Å"melanoma in situ†. During that stage, the growth does not venture beyond the very most superficial layer of skin, the epidermis. In a second stage, melanoma can penetrate the lower layer of the skin, the dermis. If the melanoma penetrates very deeply into the dermis, it may progress to a vertical growth phase – in which it can metastasize, or spread throughout body. Melanoma more often shows up on the trunk of the body and on the arms and legs, it can develop on any part of the body – including those never exposed to the sun. 14) A large proportion of skin cancers can be prevented and, if not prevented, they are curable if recognised and treated when at early stage of development. UV can also damage the surface of the eye, called the cornea, and cause cataracts, macular degeneration, scarring on the cornea and skin cancer of the eyelids and area around the eye. UVB can cause a sunburn on the cornea, the clear membrane that covers the front of your eyes. Corneal sunburn, called photokerastitis, can occur after long hours at the beach or on the ski slopes without sunglasses or goggles. It is not permanent, but it can be painful and cause temporary vision loss. Sun damage can also cause scars on the surface of the eye, called pinquecula, which are raised, yellowish, benings lumps that grow near the nose. These can be removed wity surgery. (8) More serious effects of UV are cataracts and macular degeneration. Cataracts – the clouding of the lens of the eye, the number one cause of reversible blindness – and macular degeneration are the leading causes of decreased vision among people older then 60. Cataracts can be treated with surgery. The UV damage to the eye is cumulative and much of it is preventable by wearing quality sunglasses or contact lenses to make sure they block UV light. They are a sunscreen for our eyes. (10) All people regardless of skin pigmentation, are susceptible to damage to their immune system as a result of UV light. The absorbtion of UV light leads to immunosuppresion. As UV light are absorbed by a human being, there is a decreased immune response. This reaction is favourable because there is no excessive swelling and damage to the skin as result of sun exposure. The drawback of decreased immune response is that when infection diseases do attack the body, a significant forceful immune reaction is needed. As a result, cancer often developes and spreads in the body because the immune systems has not the strenght to fight it due its suppresion by damage UV light. Other immune system damage is seen in the form of skin hypersensitivity and reactions to certain medications. UV light is very dangerous to the human immune system and should be avoided to prevent cancer and other infectious, life-threatening diseases. (16) Cold injuries result from overxposure to cold air or water and occur in two major forms: localised injuries (such as frostbite) and systemic injuries (such as hypothermia). (4) The risk of serious cold injuries, especially hyporthermia, is increased by youth, lack of insulating body fat, wet or inadequate clothing, old age, drug abuse, cardiac disease, smoking, fatigue, hunger and depletion of caloric reserves, and excessive alcohol intake (which draws blood into capilaries and away from body organs). (1) Frostbite is a medical condition that can happen to anyone. It is when the skin and/or tissue under the skin freezes and causes cell damage. This is caused by exposure to cold, either through the air or through a chemical exposure. When people are exposed to cold with the extremities including their feet, hands, nose, ears, and face being at the highest risk, the blood vessels constrict. This is a natural reaction to prevent body heat loss and hyporthermia. With the loss of warming blood flow the fluid within cells and tissues start to freeze forming ice crystals. These ice crystals take up more room within the cells then when in a fluid state, and cause the cells to rupture. Also, sudden warming can cause the cells rupture. Under extreme conditions frostbite can occur in seconds. Factors like wind chill, alcohol consumption, getting wet or being damp and how long you are exposed to the cold all impact how quickly and how severe frostbite can be. The elderly, young children, people with circulation disorders, and people from tropical climates have a higher risk factor of getting frostbite. People who have had previous cold injuries are also particularly at risk of getting injuries again in the same places. Frostbite comes in three levels of severity or degrees: *First degree, also called frost nip. It presents itself as numbed skin that has turned white in colour. The skin may feel stiff to the touch, but the tissue under is still warm and soft. There is very little chance of blistering, infection or permanent scarring as long as it is treated properly. *Second degree, superficial frostbite. It is a serious medical condition that needs to be treated by a trained medical professional. The skin will be white or blue and will feel hard or frozen. The tissue underneath is still undamaged. Blistering is likely which is why medical treatment should be sought out. Proper treatment is critical to prevent severe or permanent injuries. *Third degree, deep frostbite. The skin is white, blotchy and/or blue. The tissue underneath is hard and cold to the touch. This is a life threatening injury. Deep frostbite needs to be treated by a trained medical professional. The tissue underneath has been damaged, in severe cases amputation may be the final resource to prevent severe infection. Blistering will happen. Proper medical treatment in a medical facility with personnel trained to deal with severe frostbite injuries is required to aid in the prevention of severe or permanent injury. (9) Prevention of frostbite is actually very simple and for the most part is based on common sense. Hypothermia is heat loss at the body core, and it results from exposure to cold with the addition of other heat loss mechanisms. A healthy person's body temperature can fluctuate between 36. 1 degrees and 37. 8 degrees. Hypothermia is considered to begin once the body temperature reaches 35 degrees, thought even smaller drops in temperature can have an adverse effects. Hypothermia is divided into two types: primary and secondary. Primary hypothermia occurs when the body's heat-balancing mechanisms are working properly but are subjected to extreme cold, whereas secondary hypothermia affects people whose heat-balancing mechanisms are impaired in some way and cannot respond adequtely to moderate or perhaps even mild cold. Primary hypothermia typically involves exposure to cold air or immension in cold water. The cold air variety usually takes at least several hours to develop, but immersion hyporthermia will occur within about an hour of entering the water, since water draws heat away from the body much faster than air does. In secondary hyporthermia, the body's heat-balancing mechanisms can fail for any numbers of reasons, including strokes, diabetes, malnutrition, bacterial infection, thyroid disease, spinal cord injuries, and the use of medications and other substances that affect the brain or spinal cord. Alcohol is one such substance. In smaller amounts it can put people at risk by interfering with their ability to recognize and avoid cold-weather dangers. In larger amounts it shuts the body's heat-balancing mechanisms. Secondary hypothermia is often a threat to the elderly, who may be on medications or suffering from illnesses that affect their ability to conserve heat. Malnutrition and immobility can also put the elderly at risk. (12) The signs and symptomps of hypothermia follow a typical course, thought the body temperatures at which they occur vary from person to person depending on age, health, and other factors. The impact of hypothermia on the nervous system often becomes apparent quite early. Coordination may begin to suffer as soon as body temperature reaches 35 degrees. The early signs of hypothermia also include cold and pale skin and intensive shivering; the latter stops between 32. 2 and 30 degrees. As body temperature continues to fall, speech becomes slurred, the muscles go rigid, and the victim becomes disoriented and experiences eyesight problems. Other harmful consequences include dehydration as well as liver and kidney failure. Heart rate, respiratory rate, and blood pressure rise during the first stages of hypothermia, but fall once the 32. 2 degrees mark is passed. Below 30 degrees most victims are comatose, and below 27. 8 degrees the heart's rhythm becomes dangerously disordered. Yet even at very low body temperatures, people can survive for several hours and be succesfully revived, thought they may be appear to be dead. (12) People who spend time outdoors in cold weather can reduce heat loss by wearing their clothing loosely and in layers and by keepimg their hands, feet, and head well covered. Because water draws heat away from the body so easily, staying dry is important. Alcohol should be avoided because it promotes heat loss by expanding the blood vessels that carry body blood to the skin. Alcohol consumption, exposure to ultra violet light and cold injurys have harmful effects on our body and its defence mechanisms. It affects virtually all areas of a person's life; socially, psychologically, physiologically and mentally. It can be easily avoided by using just a little common sense.