thumb, 1865, during the American Civil War
Death
is the irreversible termination of the biological functions that define a living organism. It refers to both a particular event and to the condition that results thereby. The true nature of the latter has for millennia been a central concern of the world's religious traditions and of philosophical enquiry. Many religions maintain a belief in either some kind of afterlife or rebirth. The effect of physical death on any possible mind or soul remains for many an open question. Within the scientific community, death is frequently associated with a belief in materialism and the complete ending of mind or consciousness. Yet despite the common notion that this is a scientific viewpoint, consciousness itself has yet to be fully understood in science and psychology, and any view about the existence or non-existence of consciousness after death therefore remains a speculative belief. [1] [2]
Humans and almost all animals die in due course from senescence. Some exceptions include the hydra, rockfish, turtles and whales, all documented to live 200 years or longer without showing signs of aging, and the biologically immortal jellyfish Turritopsis nutricula. [3] Intervening phenomena which commonly bring about death earlier include malnutrition, disease, or accidents resulting in terminal physical injury. In the animal kingdom, predation is a cause of death for many species. Intentional human activity causing death includes suicide, homicide, and war. Roughly 150,000 people die each day across the globe. [4] Death in the natural world can also occur as an indirect result of human activity: an increasing cause of species depletion in recent times has been destruction of ecosystems as a consequence of the widening spread of industrial technology. [5]
Death in this context is now seen as less an event than a process: conditions once considered indicative of death are now reversible. [6] Where in the process a dividing line is drawn between life and death depends on factors beyond the presence or absence of vital signs. In general, clinical death is neither necessary nor sufficient for a determination of legal death. A patient with working heart and lungs determined to be brain dead can be pronounced legally dead without clinical death occurring. Precise medical definition of death, in other words, becomes more problematic, paradoxically, as scientific knowledge and technology advance.
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DECEASED TICKETS
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Death in biology
Natural selection
Death is an important part of the process of
natural selection. Organisms that are less
adapted to their current environment than others are more likely to die having produced fewer offspring, reducing their contribution to the
gene pool of succeeding generations. Their genes are thus eventually bred out of a population, leading to processes such as
speciation and
extinction. It should be noted, however, that
reproduction plays an equally important role in determining survival. For example, an organism that dies young but leaves many offspring will have a much greater
Darwinian fitness than a long-lived organism which leaves only one.
Extinction
Extinction is the cessation of existence of a
species or group of
taxa, reducing
biodiversity. The moment of extinction is generally considered to be the death of the last individual of that species (although the
capacity to breed and recover may have been lost before this point). Because a species' potential
range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as
Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the
fossil record) after a period of apparent absence. New species arise through the process of
speciation, an aspect of
evolution. New varieties of organisms arise and thrive when they are able to find and exploit an
ecological niche — and species become extinct when they are no longer able to survive in changing conditions or against superior competition.
After death the remains of an organism become part of the
biogeochemical cycle. Animals may be
consumed by a
predator or a
scavenger.
Organic material may then be further decomposed by
detritivores, organisms which recycle
detritus, returning it to the environment for reuse in the
food chain. Examples of detritivores include
earthworms,
woodlice and
dung beetles.
Microorganisms also play a vital role, raising the temperature of the decomposing matter as they break it down into yet simpler molecules. Not all materials need be decomposed fully, however.
Coal, a
fossil fuel formed over vast tracts of time in
swamp ecosystems, is one example.
Evolution of aging
Enquiry into the evolution of aging aims to explain why so many living things and the vast majority of animals weaken and die with age (a notable exception being
hydra, which may be
biologically immortal). The evolutionary origin of
senescence remains one of the fundamental puzzles of biology. Gerontology specializes in the science of human aging processes.
Defining death
Problems of definition
thumb, Death and
Time
One of the challenges in defining death is in distinguishing it from
life. Death would seem to refer to either the moment at which life ends, or when the state that follows life begins. However, determining when death has occurred requires drawing precise conceptual boundaries between life and death. This is problematic however because there is little consensus over how to define life. Some have suggested defining life in terms of consciousness. When consciousness ceases, a living organism can be said to have died. One of the notable flaws in this approach is that there are many organisms which are alive but probably not conscious (for example, single-celled organisms). Another problem with this approach is in defining consciousness, which remains a mystery to modern scientists, psychologists and philosophers. This general problem of defining death applies to the particular challenge of defining death in the context of medicine.
Historically, attempts to define the exact moment of a human's death have been problematic. Death was once defined as the cessation of
heartbeat (
cardiac arrest) and of
breathing, but the development of
CPR and prompt
defibrillation have rendered that definition inadequate because breathing and heartbeat can sometimes be restarted. Events which were
causally linked to death in the past no longer kill in all circumstances; without a functioning heart or lungs, life can sometimes be sustained with a combination of
life support devices,
organ transplants and
artificial pacemakers.
Today, where a definition of the moment of death is required, doctors and coroners usually turn to "
brain death" or "biological death" to define a person as being clinically dead; people are considered dead when the electrical activity in their brain ceases. It is presumed that an end of electrical activity indicates the end of
consciousness. However, suspension of consciousness must be permanent, and not transient, as occurs during certain
sleep stages, and especially a
coma. In the case of sleep,
EEGs can easily tell the difference.
The possession of brain activities, or ability to resume brain activity, is a
necessary condition to legal personhood in the United States. "
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))
Many have challenged the idea that brain death is equivalent to the cessation of consciousness. Critics point out that much of human consciousness is embodied in numerous body parts and that the end of electrical impulses in the brain does not necessarily indicate that this embodied consciousness has also ceased. Given this possibility, brain death does not necessitate the end of consciousness, and thus brain dead people may still be alive. Furthermore, some have argued, even if brain death does mean the end of consciousness for a human being, the whole notion that cessation of consciousness indicates death is problematic. Critics note the existence of many single-celled organisms such as bacteria that we consider to be alive but which many doubt are conscious. If life does not require consciousness, defining death in terms of "brain death" is a dubious procedure, even if the brain is the seat of consciousness. Thus while legal concerns surrounding death force us to develop a working definition of death, it is not at all clear that the current American definition, according to brain death, coincides at all with a definition that can be reasonably endorsed.
[who?]
Those people 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. Eventually it is possible that the criterion for death will be the permanent and irreversible loss of
cognitive function, as evidenced by the death of the
cerebral cortex. All hope of recovering human thought and
personality is then gone given current and foreseeable medical technology. However, at present, in most places the more conservative definition of death — irreversible 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
Terri Schiavo case brought the question of brain death and artificial sustenance to the front of
American politics.
Even by whole-brain criteria, the determination of brain death can be complicated. EEGs can detect spurious electrical impulses, while certain
drugs,
hypoglycemia,
hypoxia, or
hypothermia can suppress or even stop brain activity on a temporary basis. Because of this, hospitals have protocols for determining brain death involving EEGs at widely separated intervals under defined conditions.
Misdiagnosed death
There are many anecdotal references to people being declared dead by physicians and then 'coming back to life', sometimes days later in their own coffin, or when
embalming procedures are just about to begin. Owing to significant scientific advancements in the
Victorian era, some people in
Britain became obsessively worried about living after being declared dead.
[8]
In cases of
electric shock, CPR for an hour or longer can allow stunned
nerves to recover, allowing an apparently dead person to survive. People found unconscious under icy water may survive if their
faces are kept continuously cold until they arrive at an
emergency room.
[9] This "diving response", in which
metabolic activity and oxygen requirements are minimal, is something humans share with
cetaceans called the
mammalian diving reflex.
As medical technologies advance, ideas about when death occurs may have to be re-evaluated in light of the ability to restore a person to vitality after longer periods of apparent death (as happened when
CPR and defibrillation showed that cessation of heartbeat is inadequate as a decisive indicator of death). The lack of electrical brain activity may not be enough to consider someone scientifically dead. Therefore, the concept of
information theoretical death has been suggested as a better means of defining when true death actually occurs, though the concept has few practical applications outside of the field of
cryonics.
There have been some scientific attempts to bring dead organisms back to life, but with limited success.
[10] In
science fiction scenarios where such technology is readily available,
real death is distinguished from reversible death.
Death and the law
By law, a person is dead if a Statement of Death or
Death Certificate is approved by a licensed medical practitioner. Various legal consequences follow death, including the removal from the person of what in legal terminology is called
personhood.
Causes of death in humans
The leading cause of death in
developing countries is
infectious disease. The leading causes of death in
developed countries are
atherosclerosis (
heart disease and
stroke),
cancer, and other diseases related to
obesity and
aging. These conditions cause loss of
homeostasis, leading to
cardiac arrest, causing loss of
oxygen and nutrient supply, causing irreversible deterioration of the
brain and other
tissues. Of the roughly 150,000 people who die each day across the globe, about two thirds — 100,000 per day — die of age-related causes.
In industrialized nations, the proportion is much higher, reaching 90%.
With improved medical capability, dying has become
a condition to be managed. Home deaths, once normal, are now rare in the developed world.
In
developing nations, inferior sanitary conditions and lack of access to modern
medical technology makes death from
infectious diseases more common than in
developed countries. One such disease is
tuberculosis, a bacterial disease which killed 1.7 million people in 2004.
[11] Malaria causes about 400–900 million cases of fever and approximately one to three million deaths annually.
[12] AIDS death toll in
Africa may reach 90-100 million by 2025.
[13] [14]
According to
Jean Ziegler, who was the
United Nations Special reporter on the Right to Food from 2000 to March 2008; mortality due to
malnutrition accounted for 58% of the total mortality rate in 2006. Ziegler says worldwide approximately 62 million people died from all causes and of those deaths more than 36 million died of hunger or diseases due to deficiencies in
micronutrients."
[15]
Tobacco smoking killed 100 million people worldwide in the 20th century and could kill 1 billion people around the world in the
21st century, the
WHO Report warned.
[16] [17]
Many leading developed world causes of death can be postponed by
diet and
physical activity, but the accelerating incidence of disease with age still imposes limits on human
longevity. The
evolutionary cause of aging is, at best, only just beginning to be understood. It has been suggested that direct intervention in the aging process may now be the most effective intervention against major causes of death.
[18]
Symptoms of death
Signs of death, or strong indications that a person is no longer alive are:
- Ceasing respiration, the body no longer metabolises
- Pallor mortis, paleness which happens almost instantaneously (in the 15–120 minutes after the death)
- Livor mortis, a settling of the blood in the lower (dependent) portion of the body
- Algor mortis, the reduction in body temperature following death. This is generally a steady decline until matching ambient temperature
- Rigor mortis, the limbs of the corpse become stiff (Latin rigor) and difficult to move or manipulate
- Decomposition, the reduction into simpler forms of matter
Autopsy
thumb turns an autopsy into a masterpiece: The
Anatomy Lesson of Dr. Nicolaes Tulp
An
autopsy, also known as a
postmortem examination
or an
obduction
, is a
medical procedure that consists of a thorough
examination of a
human corpse to determine the cause and manner of a person's death and to evaluate any
disease or
injury that may be present. It is usually performed by a specialized
medical doctor called a
pathologist.
Autopsies are either performed for legal or medical purposes. A forensic autopsy is carried out when the cause of death may be a criminal matter, while a clinical or academic autopsy is performed to find the medical cause of death and is used in cases of unknown or uncertain death, or for research purposes. Autopsies can be further classified into cases where external examination suffices, and those where the body is dissected and an internal examination is conducted. Permission from
next of kin may be required for internal autopsy in some cases. Once an internal autopsy is complete the body is generally reconstituted by sewing it back together. Autopsy is important in a medical environment and may shed light on mistakes and help improve practices.
A "necropsy" is an older term for a postmortem examination, unregulated, and not always a medical procedure. In modern times the term is more often used in the postmortem examination of the corpses of animals.
Life extension
Life extension refers to an increase in
maximum or
average lifespan, especially in humans, by slowing down or reversing the
processes of aging. Average lifespan is determined by vulnerability to
accidents and age or lifestyle-related afflictions such as
cancer, or
cardiovascular disease. Extension of average lifespan can be achieved by good
diet,
exercise and avoidance of hazards such as
smoking. Maximum lifespan is determined by the rate of
aging for a species inherent in its
genes. Currently, the only widely recognized method of extending maximum lifespan is
calorie restriction. Theoretically, extension of maximum lifespan can be achieved by reducing the rate of aging damage, by
periodic replacement of damaged tissues, or by
molecular repair or
rejuvenation of deteriorated cells and tissues.
Researchers of life extension are a subclass of
biogerontologists known as "biomedical
gerontologists". They try to understand the nature of aging and they develop treatments to reverse aging processes or to at least slow them down, for the improvement of health and the maintenance of youthful vigor at every stage of life. Those who take advantage of life extension findings and seek to apply them upon themselves are called "life extensionists" or "longevists". The primary life extension strategy currently is to apply available anti-aging methods in the hope of living long enough to benefit from a complete cure to aging once it is developed, which given the rapidly advancing state of biogenetic and general medical technology, could conceivably occur within the lifetimes of people living today.
Death in culture
Death is the center of many traditions and organizations, and is a feature of every culture around the world. Much of this revolves around the care of the dead, as well as the
afterlife and the disposal of bodies upon the onset of death. The
disposal of human corpses does, in general, begin with the
last offices before significant time has passed, and ritualistic ceremonies often occur, most commonly interment or
cremation. This is not a unified practice, however, as in
Tibet for instance the body is given a
sky burial and left on a mountain top.
Mummification or
embalming is also prevalent in some cultures, to retard the rate of
decay.
Legal aspects of death are also part of many cultures, particularly the settlement of the deceased
estate and the issues of
inheritance and in some countries,
inheritance taxation.
Capital punishment is also a divisive aspect of death in culture. In most places that practice capital punishment today, the death penalty is reserved as punishment for premeditated
murder,
espionage,
treason, or as part of
military justice. In some countries, sexual crimes, such as
adultery and
sodomy, carry the death penalty, as do religious crimes such as
apostasy, the formal renunciation of one's religion. In many
retentionist countries,
drug trafficking is also a capital offense. In China
human trafficking and serious cases of
corruption are also punished by the death penalty. In militaries around the world
courts-martial have imposed death sentences for offenses such as
cowardice,
desertion,
insubordination, and
mutiny.
[19]
Death in warfare and in
suicide attack also have cultural links, and the ideas of
dulce et decorum est pro patria mori,
mutiny punishable by death, grieving relatives of dead soldiers and
death notification are embedded in many cultures. Recently in the western world, with the supposed increase in terrorism following the
September 11 attacks, but also further back in time with suicide bombings,
kamikaze missions in
World War II and suicide missions in a host of other conflicts in history, death for a cause by way of suicide attack, and
martyrdom have had significant cultural impacts.
Suicide in general, and particularly
euthanasia are also points of cultural debate. Both acts are understood very differently in contrasting cultures. In
Japan, for example, ending a life with honor by
seppuku was considered a desirable death, whereas according to traditional Christian and Islamic cultures, suicide is viewed as a sin. Death is
personified in many cultures, with such symbolic representations as the
Grim Reaper,
Azrael and
Father Time.
See also
- Bardo Thodol
(Tibetan Book of the Dead
)
- Burial
- Black Death
- Cadaveric spasm
- Death, Desire and Loss in Western Culture
by Jonathan Dollimore
- Death erection
- Death messengers
- Death (personification)
- Death rattle
- Día de los Muertos (Day of the Dead)
- Dying declaration
- Euphemisms for death
- Karoshi
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- Last rites
- Leading preventable causes of death
- Legal death
- List of causes of death by rate
- List of natural disasters by death toll
- List of wars and disasters by death toll
- Mortician
- Near-death experience
- Post Mortem Interval
- Pseudocide
- Thanatology
- World War I casualties
- World War II casualties
- Zombie
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References
- http://www.newscientist.com/article/mg19225780.073-the-big-questions-what-is-consciousness.html?full
- Facing up to the problem of consciousness
- Emerging Area of Aging Research: Long-lived Animals with "Negligible Senescence"
- Life Span Extension Research and Public Debate: Societal Considerations
- Human Activities Cause of Current Extinction Crisis, accessed 7 April 2009
- Title Unavailable
- Guns, Germs, and Steel
- As reflected from at least one article of literature by authors like Edgar Allan Poe, where subjects were buried alive.
- Limmer, D. et al. (2006). Emergency care (AHA update, Ed. 10e). Prentice Hall.
- Blood Swapping Reanimates Dead Dogs
- World Health Organization (WHO). Tuberculosis Fact sheet N°104 - Global and regional incidence. March 2006, Retrieved on 6 October 2006.
- USAID’s Malaria Programs
- Aids could kill 90 million Africans, says UN
- ''AIDS Toll May Reach 100 Million in Africa'', Washington Post
- Jean Ziegler, ''L'Empire de la honte'', Fayard, 2007 ISBN 978-2-253-12115-2 p.130.
- ''Tobacco Could Kill One Billion By 2100, World Health Organization Report Warn''s
- ''Tobacco could kill more than 1 billion this century: World Health Organization''
- Longevity dividend: What should we be doing to prepare for the unprecedented aging of humanity?
- Shot at Dawn, campaign for pardons for British and Commonwealth soldiers executed in World War I