Introduction:
The skin is the largest organ in our body. It not only makes us look good, it also serves as our first defence against pathogens.

How is the skin structured to serve such important functions? Roughly, the skin is made up of three layers: the epidermis, the dermis and the hypodermis layer.

The Epidermis
The visible outlayer of our body is the epidermis layer. This layer has 5 sublayers that are mostly made up of keratinocytes, roughly about 90 to 95%. The epidermis layer regenerate for about every 30 days. In the regeneration process, the new skin cells migrate and mature from the deepest 5th layer to the out most epidermis layer.

The dead skin cells are then shedded at the surface. Our skin cell also secrets oil(lipids), proteins to the surface. The lipids and proteins, combines with the dead cells, forms a temporary protective barrier as a protection of our body to the various envrionmental factors. In addition to that, one type of the skin cell - Langerhans cells is also a type of immune cells that forms the first immune defence towards pathogens in our skin.

At the base of the epidermis, we also have pigment cells called melanocytes, those cells produce melanin that gives our skin colors and tones. Melanin is known to protect us from harmful UV rays.

The epidermis is not very thick in comparing to the other two layers. It also does not have it's own blood supplies.

In addition to that, different regions in our body have different thickness in the epidermis layer. Our face's epidermis is the thinnest.

We need to have all those factors under consideration when we think about our skin care.