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The heart is a vital organ in our body, as it drives blood circulation. I was wondering if a heart keeps beating if it is separated from the body? If yes, then why?

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    $\begingroup$ This is more like a homework question. Please put in some effort towards answer. $\endgroup$ – WYSIWYG Jun 13 '15 at 8:40
  • $\begingroup$ @WYSIWYG I seriously have no idea if it is homework question or not but before asking I do searched in google which states that heart has its own electrical impulse but I wanted to know that is there anything else happen while our heart is seperated. I have never face this situation but for sure you are much experienced than me so I'll make sure to show my efforts when I will ask any sort of homework question next time . thanks $\endgroup$ – Shashank Jun 13 '15 at 8:55
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    $\begingroup$ You have heard of heart transplants I suppose. What I am saying is that you should try avoiding one line questions. Add whatever you got from google and make the question precise. You can check some meta posts on "homework". Homework is not in strict sense something that you get in your school. It is in the sense of asking - "have you done your part of work i.e. homework, before asking others". $\endgroup$ – WYSIWYG Jun 13 '15 at 9:02
  • $\begingroup$ That's true no doubt on that .. I'll make sure to make question precise. $\endgroup$ – Shashank Jun 13 '15 at 9:21
  • $\begingroup$ Don't try this at home $\endgroup$ – Hagen von Eitzen Jun 13 '15 at 21:49
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Short version The heart has the ability to beat independently of the brain as long as it has oxygen. The heart will eventually stop beating as all bodily systems begin to stop working shortly after brain death. Remember the heart can beat, but your diaphragm and lungs wont. hence the cardiac muscles undergo asphyxiation and die off. However, immediately after death, there is enough oxygenated blood in the body to keep thing moving for a while

Long version There is a simple explanation why.

As you know every muscle in the body has to receive stimuli from the neuromuscular junctions (and subsequently the nervous system) in order to contract.

The heart is a bit different in that it is not regulated by the brain, but the regulatory mechanisms lie within the heart itself. The heart conductive system contains a special group of cells called the pace maker cells (SA node) that fire at regular intervals and cause the heart to beat.

enter image description here

Each heart beat is triggered by an electrical pacemaker - a group of cells in the heart that have the ability to generate electrical activity. They cause electrical impulses to spread over the heart and make it contract. The largest natural pacemaker of the heart is called the sinoatrial or SA node and is found in the right atrium. From it, specialised groups of cells that carry the electrical charge lead off to the rest of the heart.

(Taken from here)

The brain regulates the rate of the heart beat sure, but it does not send the signals that cause the heart to beat in itself.

In short, even after disconnection, the SA node still sends the impulse down the AV node and purkinje fibres that spread out across the cardiac musculature and cause them to contract, causing the heart to beat. This will continue for a while till they run out of energy and stop.

You can read more about it here:Wiki

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  • $\begingroup$ -1 because too generic answer, too copy-pasted and little understanding. Recent research not previewed. To just say that there are that and that pacemaker in heart is not sufficient. More about why -part is needed. Beat itself is not the only process there. There is much more there if you think, for instance, the system in homeostasis. For instance, how are pacemakers kept functional? $\endgroup$ – Léo Léopold Hertz 준영 Jun 13 '15 at 8:09
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    $\begingroup$ KCl is eliminated through normal metabolic processes (kidneys). It cannot be "washed off". The heart is then electrically defibrillated. $\endgroup$ – Raoul Jun 13 '15 at 9:34
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    $\begingroup$ @RoverEye One article is The sinoatrial node, a heterogeneous pacemaker structure by Boyett. However, it is not sufficient itself. Much things, I would rewrite completely and extend. Koivumäki et all In Silica ... article is about AF and some introduction for the cell-tissue-organ model in Computational Biology. Clustering, neuronal networks, analysis through different methods and their application - you must understand this from some sources which are outside of Biology. I will let you know when some of better reviews are published in this area. $\endgroup$ – Léo Léopold Hertz 준영 Jun 13 '15 at 10:39
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    $\begingroup$ @Masi If you recommend extended revision, might i suggest you formulate your own answer for this, and that way the OP can have a more complete picture? I'll try and edit as much as can, but you clearly have more to say in this case,, and it appears that you can do it more justice. $\endgroup$ – Rover Eye Jun 13 '15 at 10:42
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    $\begingroup$ Personally, I think this answer is fine... "Does the heart keep beating? Yes, for a while, because it has a built in pacemaker". All the KCI, Kidney, etc (other junk) is good information to have - knowledge is power - but ancillary to actual SIMPLE question. If someone asks how a car engine works, we don't need to learn how brakes make the car stop... $\endgroup$ – WernerCD Jun 13 '15 at 16:38
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Sydney Ringer showed in 1882 that when the heart, when separated from the body and immersed in lactated Ringer's solution, or even isotonic saline solution, will beat because it has its own pacemaker systems at the level of the Sinoatrial node and Atrioventricular node. This activity will continue until there is insufficient ATP to support it energetically.

The Ringer sources link.

Miller, David J. "Sydney Ringer; physiological saline, calcium and the contraction of the heart." The Journal of physiology 555.3 (2004): 585-587.

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  • $\begingroup$ Can you provide sources for your answer? $\endgroup$ – March Ho Jun 12 '15 at 22:02
  • $\begingroup$ @MarchHo Yes, of course, I can. However, the question itself is a part of common knowledge, thus I gave a short answer. Will update a little bit later. $\endgroup$ – Ilan Jun 13 '15 at 6:26
  • $\begingroup$ @MarchHo As you can see, the answer is known for more than 100 years, thus I did not see any need to expand it more. onlinelibrary.wiley.com/store/10.1113/jphysiol.2004.060731/… $\endgroup$ – Ilan Jun 13 '15 at 6:35
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    $\begingroup$ @MarchHo Did you read the article until the role of Ringer assistant that had ADHD? Amazing... $\endgroup$ – Ilan Jun 13 '15 at 7:09
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    $\begingroup$ Can you please add text here instead of such a big picture which is difficult to read. $\endgroup$ – Léo Léopold Hertz 준영 Jun 13 '15 at 10:41
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I was wondering if a heart keeps beating if it is separated from the body?

Yes, it does. Here's a video showing it (don't click if you're squeamish!): https://www.youtube.com/watch?v=NEuSCPifKhA

It's a classical physiology experiment to remove a heart and keep it beating for some time in a jar with liquid solution. In fact, acetylcholine, the first neurotransmitter to be discovered, was detected via an experiment involving disembodied, still-beating frog hearts. As a result, Otto Loewi (who conducted the experiment) received the Nobel prize.

Of course it won't go on forever, as the heart eventually runs out of nutrients and air (without access to lungs). There are also other problems. Taking steps such as supplying oxygenated blood, putting the heart in an isotonic solution, ensuring stable temperature, adding adrenaline (which stimulates the heart) can extend the duration of beating.

If yes, then why?

Why not? Tissue doesn't die the moment it's removed from the body (it's not like individual cells can telepathically tell they've been cut off, they have no way of knowing). It lives for some time before nutrients are exhausted, blood in capillaries drains off, oxygen is depleted, temperature falls, desiccation occurs, and cells finally die. Note how when an accident severs body parts, they can often be surgically reattached and function normally.

Most tissues don't seem to be doing much when you sever them. For instance, a severed hand won't make any movements (actually severed animal limbs can often keep on twitching) but that is because no signal is coming from the brain. If you could emulate the signal, you could get it to move before necrosis occurs.

The heart has a central cluster of neurons, who's function is to generated a regular signal which causes the heart to beat. Because of this, the heart muscle continues to receive a signal even if cut out. The pacemaker cells don't keep perfect rhythm (and more over heart rate is a complicated matter), so in a normal human the brain fine-tunes the rate of beating through hormones and the vagus nerve. If you cut off the vagus connection, the beating won't be as ragular or as rapid as inside the body.

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  • $\begingroup$ Can you please describe this more closer a central cluster of neurons. $\endgroup$ – Léo Léopold Hertz 준영 Jun 13 '15 at 8:14
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In order to clear some issues with the question and answers I add this one.

The question itself was "will a heart keeps beating if it is separated from the body?"

The answer to this question as it was asked: No, the heart removed from the body "as is" will stop beating almost immediately. Denervation and stopping oxygen and electrolytes supply will cause short fibrillation and eventual asystole.

However, if we convert the question to "What are the conditions that will allow the denervated heart to keep beating?", the answer will be different:

If you supply it with solution of electrolytes it will continue beating for some time. If one want extend that time - other chemical compounds should be added as well as the temperature of the organ should be artificially lowered.

nice link that says exactly the same as my answer (provided by @RoverEye )

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  • $\begingroup$ I'm sorry mate, but that is not the case. If you remove it completely it still continues to beat for a while. I have seen it first hand, and @Superbest has linked a youtube video showing the same. If we supply it with electrolytes, it will beat longer, but the heart beats without them also. $\endgroup$ – Rover Eye Jun 13 '15 at 17:23
  • $\begingroup$ @RoverEye The heart on the video is partly emerged into the solution. Some hearts will beat more or less, but in general I am sure this answer is more precise. If you were right... people will never "die" if their heart is ok at the death time, their heart will beat indefinitely, but it is not the case. $\endgroup$ – Ilan Jun 13 '15 at 17:29
  • $\begingroup$ I am afraid there is a misunderstanding here. The heart is part of the autonomic nervous system and thus has the ability to beat independently of the brain as long as it has oxygen. The heart will eventually stop beating as all bodily systems begin to stop working shortly after brain death. Remember the heart can beat, but your diaphragm and lungs wont. hence the cardiac muscles undergo asphyxiation and die off. However, immediately after death, there is enough oxygenated blood in the body to keep thing moving for a while. A quick google gives enough evidence for this. $\endgroup$ – Rover Eye Jun 13 '15 at 17:38
  • $\begingroup$ @RoverEye the question is about heart "REMOVED from the body" :) $\endgroup$ – Ilan Jun 13 '15 at 17:40
  • $\begingroup$ It doesn't matter where the heart is. It can be on a plate for what the heart cares.The heart is a self contained system as far as things go for contraction. As long as it receives electrolytes and most importantly oxygen, it will beat. You might want to read this: madsci.org/posts/archives/2001-03/986058306.Gb.r.html $\endgroup$ – Rover Eye Jun 13 '15 at 17:42

protected by Mad Scientist Jun 13 '15 at 17:26

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