Skin
The largest organ in the body is skin. It consists of three layers:
Ultraviolet radiation passes into the skin damaging the cells. This may lead to sunburn and the skin can appear red. If there is a lot of sun exposure there can be a change in the genetic material (DNA) in the cells and this may lead to the growth of a tumour. If you spread your skin out it would be a strip one metre long and 1.8 metres wide. New skin grows continually and old skin flakes off (cockroach food). Skin is renewed every 28 days. There are 6 million skin cells per square centimetre. Every minute you lose more than 30 000 skin cells. When you drink water your skin swells.
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