Devoir de Philosophie

Death and Dying - biology.

Publié le 11/05/2013

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Death and Dying - biology. I INTRODUCTION Death and Dying, the irreversible cessation of life and the imminent approach of death. Death involves a complete change in the status of a living entity--the loss of its essential characteristics. II PHYSIOLOGY Death occurs at several levels. Somatic death is the death of the organism as a whole; it usually precedes the death of the individual organs, cells, and parts of cells. Somatic death is marked by cessation of heartbeat, respiration, movement, reflexes, and brain activity. The precise time of somatic death is sometimes difficult to determine, however, because the symptoms of such transient states as coma, faint (see Fainting), and trance closely resemble the signs of death. After somatic death, several changes occur that are used to determine the time and circumstances of death. Algor mortis, the cooling of the body after death, is primarily influenced by the temperature of the immediate environment. Rigor mortis, the stiffening of the skeletal muscles, begins from five to ten hours after death and disappears after three or four days. Livor mortis, the reddish-blue discoloration that occurs on the underside of the body, results from the settling of the blood. Clotting of the blood begins shortly after death, as does autolysis, the death of the cells. Putrefaction, the decomposition that follows, is caused by the action of enzymes and bacteria. Organs of the body die at different rates. Although brain cells may survive for no more than 5 minutes after somatic death, those of the heart can survive for about 15 minutes and those of the kidney for about 30 minutes. For this reason, organs can be removed from a recently dead body and transplanted into a living person. III DEFINITION OF DEATH Ideas about what constitutes death vary with different cultures and in different epochs. In Western societies, death has traditionally been seen as the departure of the soul from the body. In this tradition, the essence of being human is independent of physical properties. Because the soul has no corporeal manifestation, its departure cannot be seen or otherwise objectively determined; hence, in this tradition, the cessation of breathing has been taken as the sign of death. In modern times, death has been thought to occur when the vital functions cease--breathing and circulation (as evidenced by the beating of the heart). This view has been challenged, however, as medical advances have made it possible to sustain respiration and cardiac functioning through mechanical means. Thus, more recently, the concept of brain death has gained acceptance. In this view, the irreversible loss of brain activity is the sign that death has occurred. A majority of the states in the United States had accepted brain death as an essential sign of death by the late 1980s. Even the concept of brain death has been challenged in recent years, because a person can lose all capacity for higher mental functioning while lower-brain functions, such as spontaneous respiration, continue. For this reason, some authorities now argue that death should be considered the loss of the capacity for consciousness or social interaction. The sign of death, according to this view, is the absence of activity in the higher centers of the brain, principally the neocortex. Society's conception of death is of more than academic interest. Rapidly advancing medical technology has raised moral questions and introduced new problems in defining death legally. Among the issues being debated are the following: Who shall decide the criteria for death--physicians, legislatures, or each person for him- or herself? Is advancement of the moment of death by cutting off artificial support morally and legally permissible? Do people have the right to demand that extraordinary measures be stopped so that they may die in peace? Can the next of kin or a legal guardian act for the comatose dying person under such circumstances? All these questions have acquired new urgency with the advent of human tissue transplantation. The need for organs must be weighed against the rights of the dying donor. As a result of such questions, a number of groups have sought to establish an individual's "right to die," particularly through the legal means of "living wills" in which an individual confers the right to withdrawal of life-sustaining treatment upon family members or legal figures. By 1991, 40 states in the United States had recognized the validity of some form of living-will arrangement, although complex questions remain to be settled in all these instances. IV PSYCHOLOGY OF DYING The needs of dying patients and their families have also received renewed attention since the 1960s. Thanatologists (those who study the surroundings and inner experiences of persons near death) have identified several stages through which dying persons go: denial and isolation (No, not me!); anger, rage, envy, and resentment (Why me?); bargaining (If I am good, then can I live?); depression (What's the use?); and acceptance. Most authorities believe that these stages do not occur in any predictable order and may be intermingled with feelings of hope, anguish, and terror. See also Thanatology. Like dying patients, bereaved families and friends go through stages of denial and acceptance. Bereavement, however, more typically does follow a regular sequence, often beginning before a loved one dies. Such anticipatory grief can help to defuse later distress. The next stage of bereavement, after the death has occurred, is likely to be longer and more severe if the death was unexpected. During this phase, mourners typically cry, have difficulty sleeping, and lose their appetites. Some may feel alarmed, angry, or aggrieved at being deserted. Later, the grief may turn to depression, which sometimes occurs when conventional forms of social support have ceased and outsiders are no longer offering help and solace; loneliness may ensue. Finally, the survivor begins to feel less troubled, regains energy, and restores ties to others. Care of terminally ill patients may take place in the home but more commonly occurs in hospitals or more specialized institutions called hospices (see Hospital). Such care demands special qualities on the part of physicians and thanatologists, who must deal with their own fear of death before they can adequately comfort the dying. Although physicians commonly disagree, the tenet that most patients should be told that they are dying is now widely accepted. This must, of course, be done with tact and caring. Many persons, even children, know they are dying anyway; helping them to bring it out into the open avoids pretense and encourages the expression of honest feelings. Given safety and security, the informed dying patient can achieve an appropriate death, one marked by dignity and serenity. Concerned therapists or clergy can assist in this achievement simply by allowing the patient to talk about feelings, thoughts, and memories, or by acting as a substitute for family and friends who may grow anxious when the dying patient speaks of death. Contributed By: Calvin J. Frederick Microsoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved.

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