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Scientific Beauty News Letter
11. Stratum Corneum –The topmost Layer of Epidermis!
The stratum corneum is the outermost of the 5 layers of the epidermis and supports strong barrier function of the skin. Understanding the structure and function of the stratum corneum is important because it is directly associated with your appearance. What you look as your skin is the stratum corneum from outside.
Trattum corneum is made up of the corneocytes, which in turn are made up protein complex that is made of tiny threads of keratin in an organized matrix.
The Protein keratin can hold large amounts of water between the fibers/ threads. The stratum corneum contains about 12-16 layers of corneocytes and each corneocyte has a mean thickness of 1 micrometer.
The thickness of the Stratum corneum varies in accordance with the Age, anatomical location dn exposure to UV radiation and friction.
In the keratinocytes of the stratum spinosum and stratum granulosum, small Lamellar bodies are formed. When the keratinocyte matures and enter into the stratum corneum, enzymes degrade the outer envelope of the lamellar bodies releasing types of lipids called free fatty acids and ceramides.
Free fatty acids and ceramides released, fuse together in the stratum corneum to form a continuous layer of lipids. This lipid bilayer plays a major role in maintaining the barrier properties of the skin.
Each corneocyte is surrounded by a protein shell cal. These proteins are extensively linked with each other, which makes it completely water insoluble. Also here the cramide lipids are attached that repel water.
Because of the water repellent action of the combination of the proteins and ceramides, water molecules are held between the lipid bilayer. This helps maintain the water balance in the stratum corneum by trapping water molecules instead of letting them absorb into the lower layers of the epidermis.
The corneocytes are hold together by specialized protein structures called corneodesmosomes, these be degraded for the skin to shed and this process is called as desquamation.
You must know one very important thing about this stratum corneum that the natural Moisturizing factors are located only in this layer. NMF components absorb water from the atmosphere and combine it with their own water content allowing the outermost layers of the stratum corneum to stay hydrated despite exposure to the elements.
Because NMF components are water soluble, they are easily leached from the cells with water contact – because of this repeated washing of face with water dries out the external layers of the epidermis giving feeling of dehydration and dryness.
Less frequent washing of the face protects the NMF in the stratum corneum.
Let us discuss in detail about the NMF in next news letter.
Credit : Rahul Phate’s
Scientific Beauty News Letter
11. Stratum Corneum –The topmost Layer of Epidermis!
The stratum corneum is the outermost of the 5 layers of the epidermis and supports strong barrier function of the skin. Understanding the structure and function of the stratum corneum is important because it is directly associated with your appearance. What you look as your skin is the stratum corneum from outside.
Trattum corneum is made up of the corneocytes, which in turn are made up protein complex that is made of tiny threads of keratin in an organized matrix.
The Protein keratin can hold large amounts of water between the fibers/ threads. The stratum corneum contains about 12-16 layers of corneocytes and each corneocyte has a mean thickness of 1 micrometer.
The thickness of the Stratum corneum varies in accordance with the Age, anatomical location dn exposure to UV radiation and friction.
In the keratinocytes of the stratum spinosum and stratum granulosum, small Lamellar bodies are formed. When the keratinocyte matures and enter into the stratum corneum, enzymes degrade the outer envelope of the lamellar bodies releasing types of lipids called free fatty acids and ceramides.
Free fatty acids and ceramides released, fuse together in the stratum corneum to form a continuous layer of lipids. This lipid bilayer plays a major role in maintaining the barrier properties of the skin.
Each corneocyte is surrounded by a protein shell cal. These proteins are extensively linked with each other, which makes it completely water insoluble. Also here the cramide lipids are attached that repel water.
Because of the water repellent action of the combination of the proteins and ceramides, water molecules are held between the lipid bilayer. This helps maintain the water balance in the stratum corneum by trapping water molecules instead of letting them absorb into the lower layers of the epidermis.
The corneocytes are hold together by specialized protein structures called corneodesmosomes, these be degraded for the skin to shed and this process is called as desquamation.
You must know one very important thing about this stratum corneum that the natural Moisturizing factors are located only in this layer. NMF components absorb water from the atmosphere and combine it with their own water content allowing the outermost layers of the stratum corneum to stay hydrated despite exposure to the elements.
Because NMF components are water soluble, they are easily leached from the cells with water contact – because of this repeated washing of face with water dries out the external layers of the epidermis giving feeling of dehydration and dryness.
Less frequent washing of the face protects the NMF in the stratum corneum.
Let us discuss in detail about the NMF in next news letter.
Credit : Rahul Phate’s
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