Stratum Corneum
Stratum Corneum — the outermost layer of the epidermis, made of flattened, non-living skin cells embedded in a matrix of barrier lipids. Often described as a brick-and-mortar structure, it is the skin's primary shield against water loss and outside irritants.
Key points
- It consists of corneocytes, flattened cells rich in the protein keratin, surrounded by structured lipids.
- The brick-and-mortar model compares corneocytes to bricks and barrier lipids to the mortar between them.
- It contains Natural Moisturizing Factor that helps retain water in the surface layer.
- Cells are continually shed and replaced as newer cells rise from deeper in the epidermis.
Frequently asked
What is the stratum corneum's main function?
It forms the skin's outermost barrier, limiting water loss from within and blocking irritants and microbes from outside.
Why is it called brick-and-mortar?
The model likens the flattened skin cells to bricks and the surrounding barrier lipids to mortar, together forming a cohesive protective layer.
Related topics
This is a foundational entry in the SYNC Skin Encyclopedia and is expanded over time. Educational information only — not medical advice.
