Skin protects our body and is our front line against the world. It is an extremely vital tissue that renews itself constantly.
Our skin serves the following purposes:
Skin is a protective barrier for the body. We realize how important our skin is when it is somehow compromised (e.g. wounded). Skin has two different layers: the epidermis and the derma.
The epidermis is the external layer. It is very thin and regenerates itself every 4-6 weeks. It has five different cell layers. It protects our body and is a shield from environmental agents. It is the first layer that's damaged if there's an injury.
The deeper part of the skin is the derma.The derma offers support, providing blood and oxygen to the skin. It has fewer cells but it has elastic fibres and collagen that tone our skin and keep it firm. The derma also makes our skin elastic and resistant to friction.
When the derma is cut, the skin's elasticity makes the edges of the wound separate from each other, leaving an open wound. This means the wound will probably heal more slowly and leave more scar tissue.
On the epidermis (the skin's surface layer), there are millions of microorganisms (on average, 1 million per sq cm of skin). Some of them are "resident," i.e. more permanent, while others are "occasional" and land on the skin accidentally. These are usually only there for brief periods of time.
Human skin, unlike inorganic materials, cannot be entirely sterile. Microorganisms are why the skin maintains its physiological balance.
However, microorganisms can sometimes be problematic. This is especially true when the continuity of the epidermis is compromised by an accidental or surgical wound.