Human biology question...

[Singular Intellect]

So I was mulling over concepts like artificial constructs versus biological ones, and it brought to mind a question that I hope a more knowledgable individual could answer.

Suppose we took your average human body and were able to stop all of it's regenerative capabilities*. How long would it take before the human body fell apart?

*For the purposes of this question, let's disregard things like stomach lining replacement as a fatal flaw in the design of the human body without constant regeneration. I'm posing the question in context of only physical damage not being repaired, how long would bones last without repairs, etc. I'm aware this is something of a gray area question, but hopefully the intention of my question is understood.

[Alyrium Denryle]

So I was mulling over concepts like artificial constructs versus biological ones, and it brought to mind a question that I hope a more knowledgable individual could answer.

Suppose we took your average human body and were able to stop all of it's regenerative capabilities*. How long would it take before the human body fell apart?

*For the purposes of this question, let's disregard things like stomach lining replacement as a fatal flaw in the design of the human body without constant regeneration. I'm posing the question in context of only physical damage not being repaired, how long would bones last without repairs, etc. I'm aware this is something of a gray area question, but hopefully the intention of my question is understood.

The answer is not long. Every time you swallow something, you take a bits of your esophagus lining off with your food. The GI tract alone would go really really fast. When you undertake strenuous activity, you release lactic acid which damages tissues, your body rebuilds them stronger and with better vascularization. That function is now gone.

The body would die on the order of days to weeks I imagine.

[Akhlut]

Skin replaces itself roughly every 27 days, so, after that with no regeneration, you lose the most important part of your body that keeps your interior interior.

[Jawawithagun]

Skin replaces itself roughly every 27 days, so, after that with no regeneration, you lose the most important part of your body that keeps your interior interior.

Before that even. Remember, they don't die and regenerate all at once. You will lose about 1/27th each day once regeneration stops, the skin growing thinner and thinner and more susceptible to damage that will rip away still viable skin cells when their dead neighbours can't support them any longer.

But even before that injuries will get you in serious trouble. Thrombocytes have a lifespan of 5-9 days and they are responsible for blood clotting. Without them wounds will not close and you will continue to bleed.

So by the time your skin starts to grow thin enough to become troublesome the contingency system will already be offline.

[Singular Intellect]

The answer is not long. Every time you swallow something, you take a bits of your esophagus lining off with your food. The GI tract alone would go really really fast. When you undertake strenuous activity, you release lactic acid which damages tissues, your body rebuilds them stronger and with better vascularization. That function is now gone.

The body would die on the order of days to weeks I imagine.

That's what I suspected. To be more specific about what I was thinking about , I was mulling over the comparison between your average car and human body. Without constant regeneration, the human body would break down very rapidly, while I'd expect a car to last significantly longer if you did nothing but fuel it until it broke down.

[someone_else]

The main point here is that the average cell lasts at best a few months in any tissue you care to list, then self-destructs and its place is take by a new cell just replicated from staminal cells that sit around the body just for this purpose.
(neurons don't, since they are special)

The human body must constantly regenerate to not become a cancerous mess in weeks, not to avoid "breaking down". Epitheliums (skin, or digestive tract) just have a cheaper way to do it (mechanical abrasion).

The same mechanism of daily regeneration is just made faster if actual physical damage occurs (cuts, broken bones, that kind of damage).

Newsflash: if bones don't "regenerate" constantly (bones are constantly eroded and rebuilt) human body dies in hours. Why? Because that "regeneration" of bones allows to keep constant the levels of calcium in blood.

I'd expect a car to last significantly longer if you did nothing but fuel it until it broke down

C'mon, that's unfair. You remove the main reason why biological beings last more than a couple weeks and then claim cars last longer?
Don't paint the car at all and make it of pure iron, and then we can talk again about who lasts longer if totally fucked up.

[AniThyng]

Heck, even a stock car if not painted and rust proofed isn't going to last all that long relative to a properly maintained car. And what about oil and coolent...

[PeZook]

It's still going to be useable for a few weeks, unlike a human body which will break down in days, and probably become impossible to use for its stated purpose much quicker.