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On average, how many cells divide each day in a human being? How long does a cell wait before dividing itself ?

I have tried to look on the internet but surprisingly the answer is difficult to find..

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  • $\begingroup$ Thats pretty hard to answer, since the proliferation rate of cells is pretty different. For example heart cells hardly ever divide while cells of the hematopietic systems do this pretty often. $\endgroup$ – Chris Feb 21 '14 at 14:22
  • $\begingroup$ This is very difficult to answer since the rate of cell division is age and also health dependent. $\endgroup$ – Karin VanMeter Oct 5 '17 at 22:22
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My first thought was this:

According to Wikipedia (citation provided)

Between 50 and 70 billion cells die each day due to apoptosis in the average human adult. For an average child between the ages of 8 and 14, approximately 20 billion to 30 billion cells die a day.

For every cell that dies a new one must be born, so there must be at least between 50 and 70 billion cell divisions to replenish these cells in an adult human (no net growth).

But then I remembered erythrocytes. Wikipedia again:

Adult humans have roughly 2–3 × 1013 (20–30 trillion) red blood cells at any given time, comprising approximately one quarter of the total human body cell number

and...

these cells live in blood circulation for about 100 to 120 days

So approximately 1% of erythrocytes are destroyed every day and must be replaced. That's 2-3 x 1011 cells formed every day, which dwarfs the cells replenished due to apoptosis (5 - 7 x 109).

Through this process [erythropoiesis] erythrocytes are continuously produced in the red bone marrow of large bones, at a rate of about 2 million per second in a healthy adult.

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  • $\begingroup$ I like the answer, but there is a problem with the math. 50-70 billion cell is 5-7 x 10e10, not 5-7 x 10e9. It is still larger than the 2-3 x 10e11 number of the blood cells by a factor of about 4, but not by a factor of about 40 which is the result of the original calculation. $\endgroup$ – Len Jan 26 '17 at 17:25
  • $\begingroup$ Thanks for spotting that Len. So the sentence that says 'That's 2-3 x 10e11 cells formed every day, which dwarfs the cells replenished due to apoptosis (5 - 7 x 10e9).' should say 'That's 2-3 x 1011 cells formed every day, which is ~4 x the cells replenished due to apoptosis (5 - 7 x 10e10). Not sure about the protocol here, do I edit my answer? $\endgroup$ – Alan Boyd May 6 '17 at 18:02
  • $\begingroup$ It's also important to note that starting point of this estimate of 50-70 billion cells has no reference in the wikipedia. D'oh! So the whole thing is on very shaky grounds. I've tried to find a paper for this statement but have come up empty so far. $\endgroup$ – SeanJ Oct 4 '18 at 10:41

protected by Community Oct 6 '17 at 5:08

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