Why do living things die?

Question

I am refering to a natural death.

Answer 1

Death is the full cessation of vital functions in the biological life. This article discusses death in the biological sense of the term, and its place in various cultures.

The process of dying
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Cell death

The body of a dead walrus on Punuk Island, in the Bering SeaNormal cellular function involves the production of free energy required for vital cellular metabolism, the production of enzymatic and structural protein, the maintenance of chemical and osmotic homeostasis of cell, and cell reproduction. During normal functions, cells require oxygen, phosphate, calcium, hydrogen, carbon, nitrogen, sulphur, nutritional substrates, ATP (which is required as a source of energy), intact cell membranes, and a steady-state activity that requires O2 consumption. Cell death may occur when any of these functions is interrupted.

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Changes after death
After death, the body core temperature falls (algor mortis). Rate and degree of the cooling depends on a number of external and cadaveric factors including the environment, clothing, body temperature at time of death and size of the body.

Furthermore, in mammals, rigor mortis begins prior to decomposition. During this process, the muscles gradually stiffen due to decreasing availability of ATP and lactic acidosis within muscle fibrils. This usually begins 2-4 hours after death, though the process may begin earlier. After 9-12 hours, or in a warm enough climate, these effects may disappear. Onset and duration of rigor mortis are influenced by environmental temperature and the degree of muscular activity prior to onset of death.

Another post mortem reaction includes livor mortis. Fibrolysins (lytic enzymes) are released from serous membranes, and cause lytic degradation of fibrinogen (which is responsible for the clotting of blood). Due to this process, blood becomes permanently incoaguable (unable to clot) within 30-60min after death. Gravitational pooling of blood results in characteristic changes in skin colour, starting with those areas that support the body on whatever surface it is lying on. This is usually seen within 2 hours of death, with the process of livor mortis reaching its maximum at 8-12 hours. The colour of the post mortem lividity differs with cause of death and environmental conditions. The distribution of the lividity depends on the position of the body and the pressure at the location.

Decomposition of a body progresses in the following stages:

Autolysis: The "self digestion" of the body driven by its own enzymes. Cell membranes lose their structural integrity, lytic enzymes are released and denature macromolecules and remaining membranes. Autolysis occurs first in the most metabolically active cells, secretory cells and macrophages.
Putrefaction: Anaerobic bacterial digestion of the remains. At the end stage of autolysis, an aerobic environment is established within the corpse. This favours the growth of anaerobic bacteria of mostly endogenous (colon fauna) and to a lesser extent exogenous (soil bacteria) origin. These bacteria degrade carbohydrates, proteins and lipids of the corpse to products such as acids and gases, resulting in colour changes, odours, bloating, and liquefaction of the corpse. The rate of putrefaction is dependent on the presence of moisture and moderate environmental temperatures.
Decay: Aerobic bacterial and fungal digestion of remains. At the end stage of putrefaction, putrefactive juices have drained away and soft tissue is shrunken. All remaining tissues are in a relatively dry state. Decay is characterized by a slow breakdown of proteins by aerobic microorganisms and leads to skeletonisation of the corpse.
Diagenisis: Decomposition of hard tissues like bone and teeth. Microorganisms (bacteria, algae, fungi) invade the bone by either following physiological channels or actively penetrating the bone substance. The latter is accomplished by excretion of acidic and/or enzymatic metabolites which results in characteristic non-physiological cavities or channels, the so called "drill channels." The invading microorganisms metabolize the organic bone matrix. The resulting metabolites destroy the surrounding mineral matrix. Furthermore, the decomposition of the mineral matrix, which is composed of crystalline calcium phosphates, is influenced by chemical factors from the environment. An acidic environment results in dissolution of calcium phosphates which partly leads to demineralisation of the bone, and partly is followed by re-crystallisation to molecules that are significantly larger than the original ones and more water soluble. These processes result in micro- and macrostructural disintegration (cracking) in the first case and progressive demineralisation in the latter.
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Determining when death actually occurs
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, but the development of CPR and prompt defibrillation posed a challenge, rendering the previous definition inadequate. This earlier definition of death is now called "clinical death", and even after it occurs, breathing and heartbeat may be restarted in some cases. Events which were causally linked to death in the past are now prevented from having an effect; even without a functioning heart and lungs, a person can be sustained with life-support devices. In addition to such extremes, there are a growing number of people who would quickly die if their organ transplants or artificial pacemakers failed.

Today, where a definition of the moment of death is required, doctors and coroners 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. However, suspension of consciousness must be permanent, and not transient, as occurs during sleep, and especially a coma. In the case of sleep, EEGs can easily tell the difference. Identifying the moment of death is important in cases of transplantation, as organs for transplant (the brain excluded) must be harvested as quickly as possible after the death of the body.

Among human beings, 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))

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. Eventually it is likely 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. However, at present, 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. Generally, in such contested cases the cause of death is anoxia. Oxygen deprivation for roughly seven minutes is sufficient to kill the cerebral cortex.

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.

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 Great Britain became obsessively worried about living after being declared dead. Being buried alive was a particular possibility which concerned many; inventors therefore created methods of alerting the outside world to one's status: these included surface bells and flags connected to the coffin interior by string, and glass partitions in the coffin-lid which could be smashed by a hammer or a system of pulleys (what many failed to realise was that the pulley system would either not work due to the soil outside the coffin, or that the glass would smash in the person's face, covering them in broken glass and earth).

A first responder is not authorized to pronounce a patient dead. Some EMT training manuals specifically state that a person is not to be assumed dead unless there are clear and obvious indications that death has occurred.[citation needed] These indications include mortal decapitation, rigor mortis (rigidity of the body), livor mortis (blood pooling in the part of the body at lowest elevation), decomposition, incineration, or other bodily damage that is clearly inconsistent with life. If there is any possibility of life and in the absence of a do not resuscitate (DNR) order, emergency workers are instructed to 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 (DOA).

In cases of electrocution, 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.[citation needed] This "diving response", in which metabolic activity and oxygen requirements are minimal, is something we share with cetaceans (whales, dolphins, etc) called the mammalian diving reflex. [citation needed]

As medical technologies advance, ideas about when death occurs may have to be reevaluated in light of the ability to restore a person to vitality after longer periods of apparent death (as has already happened when cessation of heartbeat was seen to be inadequate as a decisive indicator of death). The lack of electrical brain activity may not be enough to consider someone truly dead. Therefore the concept of information theoretical death has been suggested as a better means of defining when true death actually occurs.

Answer 2

I was told that when God parted from man and sent him away to earth, it was a very emotional moment for God and soul of man, man cried a lot and begged to God not to separate him from God who loved him so much. God also felt pity and wanted his best creature back one day, so he promised human that he will surely call him back one day, that soul of man will be back in heaven with God once again, but for that he will have to sacrifice is body which is called death as per our thinking. And this is the reason why we die natural death. You must have noticed some times that there is a glowing smile on face of a dead person, I think it is because he is happy due to his reunion with Great God

Answer 3

for any begining there should be an end, so naturally anything that is born and starts living it should die to stop the living this is nature. For more details read Bhagavad Gita and you will get indepth knowledge regarding life & death.

Answer 4

Death is not natural. All things die due to outside influence.

Answer 5

Cell death

Answer 6

Because sin entered the world through the seduction of the woman and the transgression of Adam. The anti-mated spirits in the material world, no longer in fellowship with the eternal spirit, cannot survive.

In short: The spirit returns to God who gave it.

There are some excellent outlines of the resulting physical decay in other responses.

Answer 7

why does a rubber band eventually break as you keep using it? Why to machines and electronics stop working eventually? things, even living things/beings eventually reach a threshhold. If disease or an accident doesn't do it, the "force" or "energy" i guess is the best way to but it, is lost. Thus some expire gently in sleep because their internal clock was up.

Answer 8

For the same reason that inanimate things quit functioning. Like a car, for example. It runs until, finally, one day it dies. Something vital, which makes it work, has ceased to function. If it can be fixed, then it continues to operate. If it cannot be fixed, it ceases to operate. When a vital part of our body ceases to function (heart, kidneys, etc.) it must be fixed or the body will cease to operate.

Answer 9

because they ages meaning the machine get exhausted.
the reaso of death of failure of cell component to work properlythis ailure is duw to over work in the past, blood vessels get harder & les & less functional for example.
its a good thing, it always remind us that here is a GOD.

Answer 10

Cells quit functioning

Answer 11

so we can call it living things and non living things..ha ha ha