Tissues in the body undergo a constant renewal over time with approximately 1% of the body renewed each day. Tissues with high regeneration capacity are the intestine skin and blood. Others tissue like bone have a slow cellular turnover
https://books.google.com.ua/books?id=AN9s2p9ZzgoC&pg=PA86&lp...

All organs are developed by the end of the first trimester, and the process continues during the rest of the gestation of the fetus growth, and after birth until the growth spurt in adolescence is over. Most people consider this to be the end stage of human growth but nothing could be more wrong. We stop growing, and throughout life cells and tissues in the human body are exposed to internal and external stress-factors which lead to injury and loss by apoptosis or necrosis. However, to sustain the function of the tissues, the affected cells need to be replaced through a process called regeneration. During our lifetime, we are growing at a constant rate with a cell turnover of about 1% of the body weight each day
http://booksite.elsevier.com/samplechapters/9780123708694/97...

На протяжении всей жизни организма в тканях происходят процессы изнашивания и отмирания клеток (физиологическая дегенерация) и замены их новыми (физиологическая регенерация). Физиологическая регенерация может быть внутриклеточной (обновление органелл) и клеточной (обновление на уровне клеток за счет пролиферации камбиальных или дифференцированных клеток). Для каждой ткани характерны специфические особенности морфологических проявлений физиологической регенерации на клеточном и субклеточном уровнях.

http://meduniver.com/Medical/gistologia/76.html

Физиологическая регенерация – это процесс клеточного обновления.
http://biology.bsmu.by/files/biology_pdf/konsp06/22.pdf