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Bone is not inert scaffolding. Cells are constantly dissolving old bone and laying down new, so the skeleton you have now is largely not the one you had a decade ago.

Bone remodelling

HealthScience

Why it matters

The idea in context

Osteoclasts break down bone tissue and osteoblasts rebuild it, in a continuous cycle that repairs micro-damage and releases calcium when the body needs it. The process responds directly to load: bone laid under strain gets stronger, which is why weight-bearing exercise builds density and why astronauts lose it rapidly in weightlessness. The balance tips with age, with breakdown outpacing rebuilding, and that shift is what osteoporosis is. The turnover rate varies by bone type, but the whole skeleton is substantially replaced over roughly a decade.

Türkçe

Aynı kart, başka bir dilde.

Kemik hareketsiz bir iskele değildir. Hücreler sürekli olarak eski kemiği eritip yenisini döşer; dolayısıyla şimdiki iskeletiniz büyük ölçüde on yıl önceki iskeletiniz değildir.
Kemik yeniden yapımı

Osteoklastlar kemik dokusunu yıkar, osteoblastlar yeniden kurar; bu sürekli döngü mikro hasarı onarır ve beden gerektiğinde kalsiyum salar. Süreç doğrudan yüke yanıt verir: Gerilim altında döşenen kemik güçlenir; ağırlık taşıyan egzersizin yoğunluk kurmasının ve astronotların ağırlıksızlıkta bunu hızla yitirmesinin nedeni budur. Denge yaşla birlikte kayar, yıkım yeniden yapımı geçer ve bu kayma osteoporozun kendisidir. Devir hızı kemik türüne göre değişir, ama tüm iskelet kabaca on yılda büyük ölçüde yenilenir.

Source trail

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Background reading: Bone remodelingAttribution and context are revised when stronger evidence appears. Corrections are welcome through the editorial page.
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