What determines the lifespan of human cells?

The maximum lifespan of a human cell is given by its differentiation status (which has a lot to do with the Hayflick limit as mentioned by Kumar Adarsh) and partly by the environment. The environment can make a cell divide more or less often. read more

Epidermic cells, forming the easily damaged skin of the body, are recycled every two weeks or so. Red blood cells, in constant motion on their journey through the circulatory system, last only 4 months. As for the liver, the human body's detoxifier, its cells' lives are quite short - an adult human liver cell has a turnover time of 300 to 500 days. read more