Death

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For other uses, see Death (disambiguation).

Death is the cessation of physical life in a living organism or the state of the organism after that event.

Contents

Interpretations of "Death"

In almost all societies, death has one or several symbols associated with it. Common symbols of death in Western cultures include the grim reaper and the color black; conversely, in certain Eastern cultures, the color white is considered symbolic of death. The grave is a metonym for death.

Biologically, death can occur to wholes, to parts of wholes, or to both. For example, it is possible for individual cells and even organs to die, and yet for the organism as a whole to continue to live; many individual cells can live for only a short time, and so most of an organism's cells are continually dying and being replaced by new ones.

Conversely, when organisms die their cells can live for some time afterward. Organs, for instance, can be removed for transplantation. They must be removed and transplanted quickly, or they too will soon die without the support of their host. Rarely, cell cultures can be "immortal" as in the case of Henrietta Lacks' HeLa cell line.

Fingernails and hair appear to grow after a person's death, as, due to bodily dehydration, the flesh pulls away from the hair and nails. In ancient times, this led to confusion about whether a body was actually dead, and added to the myth of vampires.

Irreversibility is often cited as a key feature of death. By definition, a dead organism cannot be brought back to life; if it were to be, that would indicate that it had never been dead. Nonetheless, many people do not believe that death is necessarily irreversible; thus some have a religious belief in bodily or spiritual resurrection, while others have hope for the eventual prospects of cryonics or other technological means of reversing what is currently thought of as death.

It has been hypothesized that a limited lifespan is a consequence of evolution not selecting for extreme longevity in most species, as evolutionary selection only need apply to the organism up to the point of reproduction; after that, except for caring for kin, the continued existence of an individual can have little effect on the survival of its gene line. A common assumption is that the Second Law of Thermodynamics dictates that all complex systems must eventually deteriorate, so it is not likely that any species could ever be immortal. However, this aspect of the Second Law of Thermodynamics only applies to closed systems, which organisms are not.

Ways of Defining Human Death: Medical, Religious, and Legal

Human death can be defined by three dramatically different but overlapping domains: medical, religious, and legal. These different domains and their imporance have evolved over time and can vary from person to person. So when talking about death, it is important to differentiate which domain we are speaking of and to have a general understanding of how each defines death.

There are various ways of defining medical death. Early in western culture, death was connected to the heart first and then later the lungs. When these stopped working, a person was dead. It was sometime later that the brain came into the equation. One of the first series tests for brain death was the Harvard brain test. The test consisted of squirting ice cold water into the patient's ear. If they screamed, they were still alive. Another test involved poking the patients foot with a pin and looking for similar results. In 1963 a device called an electroencephalogram (EEG) was invented that could very accurately measure the electrical output of the brain. The test showed that when the machine registered zero electrical output from a person's brain (also known as a flat EEG) for 36 hours, the patient could be considered dead. We now know that a person can continue to be medically alive until their brain stem dies. Patients in a persistent vegetative state still have an active brain stem.

Legally, a person can be pronounced dead in three different ways. By far the most common is pronouncement by a medical doctor. The second most common is pronouncement by a coroner or a state medical examiner. The third way a person can be pronounced legally dead is by the courts; after a person has disappeared for some time, the courts will pronounce them dead so that their property can be distributed appropriately. A death certificate is a legal document which states how and when a person died, and who pronounced them dead.

In religous terms, death is believed to refer to the departure from the body of the soul, or essence. Various tests have been devised to test whether the soul has left the body, including weighing the body before and after death. See the section below for concepts on what happens to a person after they die.

When is a person dead?

How can we identify the exact moment at which death has occurred? This seems important, because identifying that moment would allow us to put the correct time on death certificates, make sure that the deceased's will is enacted only after the deceased is truly deceased, and, in general, guide us in emotional behavior regarding death. In particular, identifying the moment of death is important in cases of transplantation, as organs must be harvested as quickly as possible after death.

Historically, attempts to define the exact moment of death have been problematic. Death was once defined as the cessation of heartbeat (cardiac arrest) and of breathing, for example, but the development of CPR and early defibrillation posed a challenge: either the definition of death was incorrect, or techniques had been discovered that really allowed one to reverse death (because, in some cases, breathing and heartbeat can be restarted). Generally, the first option was chosen. (Today this definition of death is known as "clinical death".)

Today, where a definition of the moment of death is required, we usually turn to "brain death" or "biological death": people are considered dead when the electrical activity in their brain ceases (cf. persistent vegetative state). It is presumed that a stoppage of electrical activity indicates the end of consciousness.

Brain activity is a necessary condition to legal personhood, and, perhaps with the exception of the fetus, it is a sufficient condition for legal personhood. "It appears that once brain death has been determined … no criminal or civil liability will result from disconnecting the life-support devices." Dority v. Superior Court of San Bernardino County, 193 Cal.Rptr. 288, 291 (1983)

However, those maintaining that only the neo-cortex of the brain is necessary for consciousness sometimes argue that only electrical activity there should be considered when defining death. In most places the more conservative definition of death (cessation of electrical activity in the whole brain, as opposed to just in the neo-cortex) has been adopted (for example the Uniform Determination Of Death Act in the United States). In 2005, the case of Terri Schiavo brought the question of brain-death and artificial sustainment to the front of American politics. However, in all cases the common cause of death is anoxia.

Even in these cases, the determination of death can be difficult. EEGs can detect spurious electrical impulses when none exists, while there have been cases in which electrical activity in a living brain has been too low for EEGs to detect. Because of this, hospitals often have elaborate protocols for determining death involving EEGs at widely separated intervals.

Medical history contains many anecdotal references to people being declared dead by physicians and coming back to life, sometimes days later in their own coffin or when embalming procedures are about to get underway. Stories of people actually being buried alive (which must assume embalming has not occurred) led at least one inventor in the early 20th century to design an alarm system that could be activated from within the coffin.

Because of the difficulties in determining death, under most emergency protocols, a first responder is not authorized to pronounce a patient dead; some EMT training manuals, for example, specifically state that a person is not to be assumed dead unless there are clear and obvious indications that death has occurred, such as mortal decapitation, rigor mortis (the stiffening of the body), dependent lividity (blood pooling in the lowest part of the body), decomposition, or incineration. If there is any possibility of life and in the absence of a do not resuscitate order, emergency workers must begin rescue and not end it until a patient has been brought to a hospital to be examined by a physician. This frequently leads to situation of a patient being pronounced dead on arrival.

It is also possible that death does not occur at a particular moment, but unfolds as a process over a period of time. Under this definition, the term "exact moment of death" loses meaning.

Cause of death in the United States

The cause of death in certain area and certain group of ages are different according to area and each group. In 2002 in the U.S. the top 10 causes of death were:

Other notable causes of death in the United States (2002)

  • Intentional Abortion: 1,293,000
    • Note that there is much debate as to when a fetus should be considered "human." The death of a human zygote — a one-celled combination of a sperm and an egg — is counted by some as the death of a human, and by others as simply the death of a cell. The above number would apparently include abortions to save the life of the mother, abortions of obviously highly defective fetuses, and abortions of fetuses unlikely to reach term.

Statistical data from: U.S. Department of Health & Human Services Death Penalty Information Center National Right To Life, and The Alan Guttmacher Institute

What happens to humans after death?

The second question is of what, apart from the cessation of metabolism and the onset of physiological processes of decay, happens, especially to humans, during and after death (or "once dead", thinking of death as a permanent state). In particular, there is the question of what becomes of consciousness or the soul. Such questions are of long standing, and belief in an afterlife (such as an underworld), or in reincarnation, are common and ancient. The belief that any and all consciousness ceases to exist at death, and that death ("after-life") itself is ultimately the exact same experience as prior to conception ("before life"), is common in atheism/agnosticism. Conversely, religious belief in and information about an afterlife is a consolation in connection with the death of a beloved one or the prospect of one's own death. On the other hand, fear of hell or other negative consequences may make death worse. Human contemplation about death is an important motivation for the development of organized religion.

Traditions exist across most cultures to mourn the death of loved ones. Many archaeologists feel that the careful burials among Homo neanderthalensis, where ochre ornamented bodies were laid in carefully dug graves, is evidence of ritualised burial. This may indicate early religious belief which, furthermore, might include a concept of an afterlife.

Physiological consequences of human death

For the human body, the physiological consequences of death follow a recognized sequence through early changes into bloating, then decay to changes after decay and finally skeletal remains.

The changes in the immediate post-death stage have received the most attention for two reasons—firstly it is the stage mostly likely to be seen by the living and secondly because of the research of forensics in potential crimes.

Soon after death (15–120 minutes depending on various factors), the body begins to cool (algor mortis), becomes pallid (pallor mortis), and internal sphincter muscles relax, leading to the release of urine, feces, and stomach contents if the body is moved. The blood moves to pool in the lowest parts of the body, livor mortis (dependent lividity), within 30 minutes and then begins to coagulate. The body experiences muscle stiffening (rigor mortis) which peaks at around 12 hours after death and is gone in another 24, depending on temperature. Within a day, the body starts to show signs of decomposition (decay), both autolytic changes and from 'attacking' organisms—bacteria, fungi, insects, mammalian scavengers, etc. Internally, the body structures begin to collapse, the skin loses integration with the underlying tissues, and bacterial action creates gases which cause bloating and swelling. The rate of decay is enormously variable; a body can be reduced to skeletal remains in days, or remain largely intact for thousands of years.

In most cultures, before the onset of significant decay, the body undergoes some type of ritual disposal, usually either cremated or deposition in a tomb, often a hole in the earth called a grave, but also in a sarcophagus, a crypt, sepulchre, or ossuary, a mound or barrow, or endlessly monumental surface structures, a mausoleum such as the Taj Mahal. In Tibet, one method of corpse disposal is sky burial, which involves placing the body of the deceased on high ground (mountain) and leave it for birds of prey to dispose of. Sometimes this is because in some religious views, birds of prey are carriers of the soul to the heavens, but other times, this simply reflects the fact that when terrain (Tibet) makes the ground too hard to dig, there aren't many trees around to burn and the local religion (Buddhism) believes that the body after death is only an empty shell, there are more practical ways of disposing a body, such as leaving it for animals to consume. On the other hand in certain cultures efforts are made to retard the decay processes before burial (resulting even in the retard of decay processes after the burial) , mummification or embalming. This happens during or after a funeral ceremony. Many funeral customs exist in different cultures.

A new alternative is "ecological burial". This involves subsequently deep-freezing, pulverisation by vibration, freeze-drying, removing metals, and burying the resulting powder, which has 30% of the body mass.

Graves are usually grouped together in a plot of land called a cemetery or "graveyard" and can be arranged by a funeral home, mortuary , undertaker or by a religious body such as a church or (for some Jews) the community's Burial Society, a charitable or voluntary body charged with these duties.

Personification of death

Main article: Death (personification)

Death is also a mythological figure who has existed in popular culture since the earliest days of storytelling. The traditional Western image of Death, known as the Grim Reaper, is employed on a tarot card and in various television shows and films. Some examples:

See also

External links

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