Layers and multitasking
The skin is an average of 2m2 in size. It literally carries out multiple tasks, because it is divided into three layers: the outer skin (epidermis), the dermis, and the subcutis.
The epidermis is the outer layer which protects the body from environmental influences. The outer skin or epidermis has no blood circulation, for the blood vessels first appear in the dermis which is found underneath it. The dermis or dermis contains various cell structures (e.g. blood vessels, hair roots, sweat glands) and many elastic fibers. Under the dermis is located the subcutis, which consists of nutrient reservoirs (the fat cell tissue) and affords protection against cold and pressure.
Why do we need skin anyway?
Our skin is a contact organ (e.g. temperature, pain). Its diverse protective functions are especially important. It provides a certain protection against:
- Cold & heat
- Pressure and collision
- Water
- Drying out
- “Chemical Substances“(e.g. alkalines, acids, water)
- Germs (e.g. bacteria, fungi, viruses)
- Ultra-violet radiation
Did you know? The skin is its “own doctor“!
For although we do not notice, the epidermis renews itself constantly! This is unique, for no other organ can do that to this extent!
As the “lowest layer of the epidermis”, the germ- or basal layer lies above the leather dermis. This is where new skin cells (keratinocytes) are formed through cell division. During their “migration” in the direction of the outer skin surface they change their appearance and develop through stages as “spinous cells” and “granular cells” to finally end as “cornified cells” (keratinocytes).
Every day we lose millions of cornified cells without noticing it. This is referred to as “desquamation”.
By the way, this complete renewal of the epidermis does in fact take longer than one might think: about 28 days, or 4 weeks!
