Saturday 26 March 2011

Understanding the skin

To describe the science behind skincare, a lot of my posts are going to be referring to the structure of the skin so I though I'd give a quick anatomy lesson on the composition of skin. 

The deepest layer of the skin is called the subcutaneous layer and it is located just below the dermis (cut off in this diagram). It is a layer of fat cells, that keep the skin looking plump and bouncy, and blood vessels which provide nutrients to the upper layers of the skin.

The dermis middle layer of the skin. The dermis is made up of collagen and elastin which maintains the structure, strength, flexibility and elasticity of the skin. Fibroblasts which are the cells in the dermis responsible for producing new collagen. The dermis also contains blood vessels, sweat and sebaceous glands and hair follicles.

The uppermost layer of the skin is the epidermis. This consists of five layers of cells and is responsible for the appearance of the skin. The deepest layer of the epidermis, the basal layer, is comprised of immature skin cells that divide then mature and move their way up through each skin layer to the surface where they then die and become part of the horny layer before they are shed. It generally takes about 4 weeks for the cells to move from the basal layer to the horny layer. The epidermis also contains melanocytes which are what gives our skin its colouring and Langerhans which are the cells that tell the body when foreign substances such as bacteria have entered the body.

Cross section of the skin (courtesy of http://www.patient.co.uk/diagram/Skin-Cross-Section.htm

Hopefully, by understanding the composition of the skin it will make it easier to understand the science behind new skin care products or the latest must have ingredient that companies are raving about.

Sarah