How long take to repair all the skin in a human body?
Answers
This is a broad based question. I shall confine my a answer to a few key points that strike my mind:
Dermal tissues (skin) are replaced quickly and as a matter of routine. A patch of skin replaces in about 25 days.
It takes about 5 months for a nail to grow/replace from bottom to top .
Liver cells regenerate very fast. liver is the only complex organ that can "grow". The liver will return to a normal size in one to two weeks following the removal of greater than 50% of the liver by mass.
Nerve cells get TERMINALLY differentiated in a mature brain and are NOT replaced.
Similarly the rod and cone cells in the retina of eye may not be replaced.
Unlike liver, cells of most of human/animal organs are terminally differentiated. For example if thumb is cut from the base the natural repair that follows never results in replacement of the thumb.
In human females egg cells (number of eggs) is preformed towards the onset of puberty. These are simply discharged one by one during the menstrual cycle till the on set of menopause.
In human males sperm cells are rapidly produces from puberty onwards till old age when these may be limited by some clinical conditions.