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I've heard that stomach lining has the fastest reproducing cells and the brain has the slowest.

Where in the human body does mitosis occur and at what rates do these cell reproduce? Is there a chart for the whole body available?

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It's not that they have different rates. The stomach epithelium just has a lot of stem cells that can divide non-stop, the brain has very few. Usually, the specialized cells in the body don't divide themselves; a small reservoir of undifferentiated stem cells (maintained for just this purpose) divides and some of the new stem cells differentiate to make more specialized cells. Specialized cells can de-differentiate and revert to stem cells sometimes, too. –  Superbest Apr 1 at 23:21
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In many cases cell division depends on the stage of development an organism is in. The rate of cell division is obviously much faster in a developing organism and from what I understand fully differentiated cells such as neuron and those in skeletal muscles don't divide (correct me if I'm wrong here).

In early development totipotent cells (stem cells that can become anything) begin to differentiate dependent on environmental factors, turning into multipotent (partially differentiated) cells that can only lead to certain cell types. For example: mesodermal precursors can differentiate to myoblasts, which can go on to differentiate into myotubes, later forming muscles.

Epithelial and and blood cells are the two of the main types of cells that need to be constantly replaced in developed organisms. As far as I know cells lining the gut epithelium are fastest to divide. They are created from stem cells in 'crypts' (pockets) in the lining and are pushed outwards, where they are later broken down (by what I would assume would be abrasion and intestinal juices). My book gives them a lifespan of 3-5 days. External skin cells are much slower to divide (though I'n not sure by exactly how much).

Red blood cells have have a lifespan of approximately 120 days. They are replenished by stem cells in the marrow of certain bones (e.g. a femur). Neutrophils are the next most common blood cell, with a circulating life of 8 hours (but lifespan may be a few days). Per day, roughly equal numbers of RBCs and neutrophils are created and are most numerous new cells created per day. Lymphocytes, another white blood cell, are responsible for immune 'memory' can persist for years. The fastest recorded mitotic cycle for a mammalian cell (in culture) is ~8-10hrs.

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But from how I understand it, blood cells are not really cells in the sense that they are just bags of haemoglobin without the standard internal organelles found in cells. –  John Smith Feb 14 '12 at 2:03
    
That's right, but they do develop from precursor cells that contain a nucleus. To be honest, I don't know of many other cells that continue dividing at a steady rate. As far as I know cells such as fibroblasts and macrophages are mainly produced in response to stimulus. There are probably other types that I am missing however... –  Ultimate Gobblement Feb 14 '12 at 2:18
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Nice answer. Can you expand the abbrvtn IIRC (not everyone would know). Red blood cells have a lifespan of approx 120days. Neutrophils are the next most common blood cell, with a circulating life of 8 hours (but lifespan may be a few days). Per day, roughly equal numbers of RBCs and neutrophils are created and are most numerous new cells created per day. Lymphocytes, another white blood cell, are responsible for immune 'memory' can persist for years. The fastest recorded mitotic cycle for a mammalian cell (in culture) is ~8-10hrs. Feel free add this in, if helpful. –  PlaysDice Apr 1 at 18:31
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Yeah sure, done :) –  Ultimate Gobblement Apr 1 at 19:03
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Question is two years old, and the answer is approx 20 yo, but I believe both are still pertinent: According to Jared Diamond on pg 12 of his Harper paper version (1993 -- but reissued in 2006) of The Third Chimpanzee, we replace intestinal lining epithelium every few days, urinary bladder lining every two months, and replace every red blood cell about every four months. So though blood cells are fast (and probably more numerous) they are slow compared to the intestinal cells!

It seems amazing that the telomeres of the intestinal walls' cells don't wear out and begin cancerous changes much earlier than they do...if the statements above are all accurate. I do find Diamond an incredibly insightful writer and think you can trust him.

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Can you add a link (or a proper citation, First author, Journal, Volume, Issue, and page number) to the answer? It makes finding the reference much easier. –  Chris Apr 1 at 12:11
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