When we’re in the bath, our skin prevents both water from moving into our bodies and essential nutrients from leaching into the tub. But because most of us don’t spend our entire lives submerged underwater, our skin’s chief role is to control how much water evaporates from our bodies. In fact, the skin’s role as a semi-impermeable barrier to fluid loss is so important that people suffering from serious burns often die, not as a direct consequence of their injuries, but from de hydration.
Each of us is covered by about 2 square meters of skin – about the area of a queen-size bed. For this waterproof suit to do its job, stem cells at the base of the skin replenish the layers above by producing a continuous stream of new cells initially like themselves and then a variety of specialised cell types. As a result of this continuous production, the specialised cells – which are destined to become the different layers of skin – move outwards until they are finally shed.
:: Read more here ::