The outermost layer of your skin
The epidermis is the uppermost layer of your skin.
It is responsible for creating skin tone andprotecting against toxins and infection.
This article describes the layers of cells in the epidermis, including their structure and function.
2007 Heather Brannon, MD licensed to About.com, Inc.
How Many Layers of Skin Are There?
There are three main layers.
The deeper hypodermis layer, also calledsubcutaneous tissue, is made up of fat and even more connective tissue.
2007 Heather Brannon, MD licensed to About.com, Inc.
Stratum Basale
The bottom layer of the epidermis is called thestratum basale.
This layer contains one row of column-shaped keratinocytes called basal cells.
Basal cells are constantly dividing and pushing already-formed cells towards the skin’s surface.
Melanocytes, the cells that produce melaninthe pigment which provides your skin its colorare also found in this layer.
Cells in this layer are responsible for making keratin.
This is the fibrous protein that gives skin, hair, and nails their hardness and water-resistant properties.
This allows them to contain a high proportion of keratin to form the rigid cell layer of skin.
There is a lot of activity in this layer.
Keratin proteins and lipids work together to create many of the cells responsible for the skin’s protective barrier.
Stratum Lucidum
Thestratum lucidumlayer is only present in the thicker skin of the palms and soles.
Its main function is to reduce friction between the stratum corneum and stratum granulosum.
Stratum Corneum
The cells in thestratum corneumlayer are known ascorneocytes(or horny cells).
These cells have flattened out and are considered dead.
They serve as an effective barrier to any chemicals that might harm the living cells just beneath them.
It ensures the continued production of new skin cells.
Summary
The epidermis is composed of layers of skin cells called keratinocytes.
In your palms and soles, there’s an additional layer called stratum lucidum underneath the stratum corneum.
In the bottom layer, keratinocytes divide and push up formed cells toward the upper layer.
The cells that reach the surface flatten and die.
This provides a barrier to keep out pathogens and protect new skin cells underneath.
National Cancer Institute.Layers of the skin.
The Nemours Foundation/Kidshealth.org.Skin, hair, and nails.
2021;89(4):e00695-20.
