Physically, what is death?

Discussion in 'Biology & Genetics' started by supernova_smash, Mar 21, 2002.

  1. supernova_smash Registered Senior Member

    Messages:
    31
    I have been wondering this for a while...what exactly happens during death? I need a better answer than your vitals stop, because just because they stop working for a moment doesn't mean they are BOOM DEAD and instantly start decomposing. If that were true, we couldn't have organ implants. Let's take an example: A heart-attack. What is happening here? I mean, obviously blood flow to the brain and othe parts of the body ceases, but how does this "kill" you? Why can't we bring people back to life, if we are basically electro-chemical machines?
     
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  3. Rick Valued Senior Member

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    3,336
    Well death has too stages(can be more if you talk above physicalities which we dont intent to discuss here)

    1)Clinical death: at this point Pulse and heart stops,you"re declared dead since heart is unable to pump out blood to various body parts,thus devoid the cell of the body of oxygen,since you lungs cease.
    2)Biological death:
    this is mainly related to brain.as soon as brain figures out that the body cant survive,it sends out messages in form of electrical signal to various organs to start the degradation process,or decaying process.Now,at this point Brain releases halucinogens(as far as i know)to produce out of body experiences(i have found one research work which says LSD and Maurijuana increases more than 250 micrograms,which is sufficient for producing great halucination.(this process primarily allows proper death to occur)that means this allows death and decay of body without much pain and trauma.

    essentially,i think primary cause of death is to escape trauma and pain so as to go into state of hallucination permanently,that is in another world as some people put it emotionally.

    if you wish you can also check the thread called <b>answer me</b>where we have discussed various points.


    bye!
     
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  5. esp Registered Senior Member

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    908
    Cessation of electrical activity in the brain is a good definition.
     
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  7. bbcboy Recovering christian Registered Senior Member

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    1,104
    On the point of organ transplantation, remember that the organs are taken from a live (Though brain-dead) person and immediately cooled to stop them degenerating. A little like the way your fridge keeps meat fresh. The organ is then transported very quickly to the recipient and warmed slightly before transplantation in a mild saline solution which also helps to keep the organ viable.

    Meanwhile the donor is taken off of the ventilator and the rest of the body dies through lack of oxygen supplied by machinery.
     
  8. Shaman Registered Senior Member

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    41
    The Ketamine Model of The Near Death Experience

    Quote:
    ____________________________________________

    Near-death experiences (NDE's) can be reproduced by ketamine via blockade of receptors in the brain (the N-methyl-D-aspartate, NMDA receptors) for the neurotransmitter glutamate. Conditions which precipitate NDE's (hypoxia, ischaemia, hypoglycaemia, temporal lobe epilepsy etc.) have been shown to release a flood of glutamate, overactivating NMDA receptors resulting in neuro ('excito') toxicity. Ketamine prevents this neurotoxicity. There are substances in the brain which bind to the same receptor site as ketamine. Conditions which trigger a glutamate flood may also trigger a flood of neuroprotective agents which bind to NMDA receptors to protect cells, leading to an altered state of consciousness like that produced by ketamine. This article extends and updates the theory proposed in 1990 (Jansen, 1990b).

    The near-death experience (NDE) is a phenomenon of considerable importance to medicine, neuroscience, neurology, psychiatry, philosophy and religon (Stevenson and Greyson, 1979; Greyson and Stevenson, 1980; Ring, 1980; Sabom, 1982; Jansen, 1989a,b, 1990b). Unfortunately, some scientists have been deterred from conducting research upon the NDE by claims that NDE's are evidence for life after death, and sensationalist media reports which impart the air of a pseudoscience to NDE studies. Irrespective of religous beliefs, NDE's are not evidence for life after death on simple logical grounds: death is defined as the final, irreversible end. Anyone who 'returned' did not, by definition, die - although their mind, brain and body may have been in a very unusual state.

    There is overwhelming evidence that 'mind' results from neuronal activity. The dramatic effects on the mind of adding hallucinogenic drugs to the brain, and the religous experiences which sometimes result, provide further evidence for this (Grinspoon and Bakalar, 1981). One of the many contradictions which 'after-lifers' can not resolve is that "the spirit rises out of the body leaving the brain behind, but somehow still incorporating neuronal functions such as sight, hearing, and proprioception" (Morse, 1989, original italics).

    All features of a classic NDE can be reproduced by the intravenous administration of 50 - 100 mg of ketamine
    ________________________________________________

    http://leda.lycaeum.org/Documents/The_Ketamine_Model_of_the_Near_Death_Experience.9264.shtml
     
  9. Shaman Registered Senior Member

    Messages:
    41
    Electrocerebral silence (ECS)

    hmm... cortical or brainstem activity?

    In case of barbituric use or hypothermia it may not be a good definition.

    Quote:
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    Montes and Conn reported ECS after near-drowning in a child aged two and a half years. The child had CPR for 30 minutes, was placed on a mechanical ventilator, had initial decerebration, and was then paralyzed with pancuronium. Phenobarbital was loaded intravenously, and a core temperature of 35°C was documented. Two hours later, an EEG was performed and described as flat in all leads. Ten hours later, EEG activity reappeared and the patient went on to recover fully. The authors suggested allowing 24 hours of observation after near-drowning before declaring brain death in children.

    This case clearly shows that caution should be used when the clinical examination or EEG is done soon after an acute insult.

    Moreover, clinicians should recognize that the existence of posturing, the use of pancuronium and phenobarbital, and hypothermia preclude the clinical diagnosis of brain death as described by the President’s Commission report and that a flat EEG alone does not diagnose brain death. Cases have been reported of successful CPR after prolonged near-drowning in children, but no documented cases are known of recovery after determination of clinical brain death.

    A review of 23 patients by Grattin-Smith et al suggested that loss of brainstem reflexes in patients with barbiturate levels of less than 40 µg/mL is not due to the action of barbiturates alone. Other intoxicants or other causes must be ruled out. However, even moderate barbiturate levels may contribute to an altered clinical picture, and the patient may appear clinically dead.

    This may have been the case in a patient reported by Kohrman and Spivack. This 3-month-old infant suffered from hypoxic ischemic encephalopathy. He was found to be unresponsive, with absent brainstem reflexes, apnea, and ECS. The phenobarbital level was 21.4 mg/mL, but 4 hours later the child regained sucking movements as well as a disorganized EEG pattern.

    Caution should be applied in diagnosing brain death when even a modest degree of intoxication has occurred, especially when the intoxication is acute.
    ______________________________________

    www.emedicine.com/neuro/topic491.htm
     
  10. scilosopher Registered Senior Member

    Messages:
    435
    Brain death, without "complete" death, only happens in the hospital due to ventilators (The brain is required for breathing but not heartbeat). You can have your heartbeat and breathing stop without brain death as all tissue in your body can survive for limited periods of time under hypoxic conditions.

    The brain doesn't signal to the body for it to decay, although tissue deprived of oxygen often induces cell death in the surrounding tissue using chemical signals (this is where most of the damage in stroke actually comes from for instance). When the brain isn't functioning the body will die because it isn't instructed to breathe.

    Cells are quite different. They do kill themselves if they aren't working right. This is one of the main protections about cancer. They can also live outside the body quite happily in the correct chemical environment. Whole tissues can therefore be maintained alive for the periods of time necessary for transplantation (there kept cold to reduce the metabolic rate of the cells so they don't become too oxygen starved).

    Life can basically be described as the ability to dynamically avoid equilibrium. In a multicellular organism there are multiple organs and systems built for providing all the cells what they need to live. Typically if any of these fails it will lead to slow degeneration and death. We can sometimes put it back on path when it's knocked off. Brain death we can't really fix (though sometimes brain dead people have been brought back) so it is considered death practically. What the best definition is unclear to me as much of your bodies tissues live for a period when you as a person are already considered dead.
     
  11. Stryder Keeper of "good" ideas. Valued Senior Member

    Messages:
    13,101
    If you look at first towards what the body is made of it gives a clue, genes and most notibly DNA. DNA is pretty much the patterning of blueprints for your whole system, how all your body fits together in the package that makes up you.

    Also located in the genetic patterning is information that changes through a mixture of things i.e. old age, drug usage, alcohol, smoking etc. This is where some forms of cancers occur due to the patterning changing.

    The pattern can even be changed via bacteria or virii. (Notibly virii change how the RNA is, so replicating strands of DNA become the cloned changed DNA/RNA where the virii proteins are "Piped" as nutrients across the body.)

    I mention all this because at the end of the day all this can tool up to the sum of what chemicals are created through brain processes, and exactly how much. On death the body no longer controls the balances of chemicals, it no longer controls the chemistry to feed anti-bodies that are fighting bacteria. In fact the anti-bodies become overwhelmed and thats pretty much when decay sets in.

    This is most notible when you look at something like Gangreen, a mixture of blood poisoning and lack of circulation, which can eventually cause mold and wrot. (If the person can live past the blood poisoning)

    Even Leprosy.

    Now that's sections of the body, wrotting before the brain stops.

    I suppose a meta-physical way of describing it is with Fish and ponds. If the water stagnates, the oxygen level drops, and the fish die due to poisoning. If the water is free flowing, then it's oxygenated, and the fish are plentiful.

    In the body terms, this means that all those stagnating chemicals start breaking down the body.
     
  12. Eflex tha Vybe Scientist Registered Senior Member

    Messages:
    190
    A spiritual death or a physical one?

    as far as the physical aspect,

    I would say that the lack of Brain Wave Activity is the best indicator of death.
     
  13. Rick Valued Senior Member

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    3,336
    Endorphins increase during death?

    What are Endorphins?

    • In 1975, Endorphins were discovered by Dr. John Hughes and Dr. Kosterlitz.
    • It has been confirmed that Endorphins have both neurological and spinal effects.
    • Twenty different types of Endorphins have been discovered in the nervous system.
    • The most effective, beta-endorphin which gives the most euphoric effect to the brain, has been found to be composed of 31 amino acids.
    • The word Endorphin is abbreviated from 'endogenous morphine' which means a morphine produced naturally in the body.
    • Endorphins are renowned worldwide as anti-stress hormones that relieve pain naturally.
    • They are secreted to remove stress or pain when you have pain or stress. In other words, they block the signal of pain to the nervous system. This being an effect that reduces the pain and causing an euphoric effect to occur.


    • Unfortunately Endorphins cannot work for a long time because our body also makes enzymes, called endorphinase, which chew up the Endorphins. This is the reason why Endorphins cannot work for a long time causing people to suffer from excruciating pain as they become old.
    • Endorphins, which have the most positive effect among hormone produced in the brain, make many of our organs healthy. When they are secreted continuously and spread to the whole body, the body becomes healthier. In short, Endorphins are the most precious gifts to human beings from God.

    I have found it amusing that Endorphins are secreted in large amounts during the decaying part of death,in the brain for undergoing hallucination.

    W

    bye!
     

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