Science / biology question -

[Guest guest]

Here are a couple references I was able to find right away that should give you

a good idea of how long it takes different cells to replace themselves:

" There are two methods of donation. A bone marrow harvest requires a two-night

stay in hospital and under general anaesthetic the cells are extracted from the

pelvic bones by sterile needle and syringe. No surgical incision is required and

the blood stem cells replace themselves within 21 days. " reference:

http://www.dailymail.co.uk/pages/live/articles/health/healthmain.html?in_article\

_id=382109 & in_page_id=1774

 

" Our bodies are comprised of cells that replace themselves by dividing. There

is a genetic limit as to how many times our cells will continue to replicate

themselves via healthy division processes. Once enough cells reach their genetic

reproductive limit, the organism (our body) is no longer able to sustain life

functions and succumbs to disease or death. " (I stated more about this in

previous posts) reference: life extension,

http://www.lef.org/magazine/mag2003/jan2003_report_carnosine_01.html

 

" Normally skin cells take about 21-28 days to replace themselves, in psoriasis

they take around 2-6 days. Normally there is a constant shedding of dead cells;

however in psoriasis because of the acceleration of the replacement process,

both dead and live cells accumulate on the skin surface. Often this causes red,

flaky, crusty patches covered with silvery scales, which are shed easily. "

reference:

http://www.nhsdirect.nhs.uk/articles/article.aspx?printPage=1 & articleId=301

 

" ...For example, our heart is new every 3 months, our stomach is new every 6

months, the roof of our mouths is new every 2 hours... " reference:

http://www.grundychiropractic.comHISTORY_FORM.pdf.

-Tiffany