Corneocyte

corneocytescornified cell envelope
Corneocytes are terminally differentiated keratinocytes and compose most if not all of the stratum corneum, the outermost part of the epidermis.wikipedia
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Stratum corneum

horny layercornified layerepidermal permeability barrier
Corneocytes are terminally differentiated keratinocytes and compose most if not all of the stratum corneum, the outermost part of the epidermis. From the site of production, lamellar bodies migrate to the top of the stratum granulosum and then into the intercellular domain of the stratum corneum to extrude their contents, which are predominantly lipids. Corneocytes, also referred to as squames (from Latin squama, meaning a “thin flake” or “scales”) are terminally differentiated, anucleated cells of keratinocyte lineage that constitute the majority of stratum corneum, the outermost layer of the epidermis.
There has been a long-standing belief in dermatology that the stratum corneum consisted of dead cells (corneocytes), devoid of biological activity and function.

Desquamation

skin peelingdesquamateddesquamating
They are regularly replaced through desquamation and renewal from lower epidermal layers, making them an essential part of the skin barrier property.
In pathologic desquamation, such as that seen in X-linked ichthyosis, the stratum corneum becomes thicker (hyperkeratosis), imparting a "dry" or scaly appearance to the skin, and instead of detaching as single cells, corneocytes are shed in clusters, forming visible scales.

Epidermis

epidermalepidermal cellsepidermal layer
Corneocytes are terminally differentiated keratinocytes and compose most if not all of the stratum corneum, the outermost part of the epidermis. They are regularly replaced through desquamation and renewal from lower epidermal layers, making them an essential part of the skin barrier property. They contain a highly insoluble cornified envelope within the plasma membrane, and lipids (fatty acids, sterols and ceramides) released from lamellar bodies within the epidermis. Keratinocytes in the stratum basale of the epidermis will multiply through cell division and migrate toward the skin surface. Corneocytes, also referred to as squames (from Latin squama, meaning a “thin flake” or “scales”) are terminally differentiated, anucleated cells of keratinocyte lineage that constitute the majority of stratum corneum, the outermost layer of the epidermis.

Keratinocyte

keratinocytesskin cellsdead skin cells
Corneocytes are terminally differentiated keratinocytes and compose most if not all of the stratum corneum, the outermost part of the epidermis. Corneocytes are keratinocytes without nuclei and cytoplasmic organelles. Keratinocytes in the stratum basale of the epidermis will multiply through cell division and migrate toward the skin surface. Corneocytes, also referred to as squames (from Latin squama, meaning a “thin flake” or “scales”) are terminally differentiated, anucleated cells of keratinocyte lineage that constitute the majority of stratum corneum, the outermost layer of the epidermis.
During this differentiation process, keratinocytes permanently withdraw from the cell cycle, initiate expression of epidermal differentiation markers, and move suprabasally as they become part of the stratum spinosum, stratum granulosum, and eventually corneocytes in the stratum corneum.

Keratin

keratinizationkeratinouskeratinized
Major constituents of corneocytes are keratin intermediate filaments organized in parallel bundles to form a matrix to give rigidity to the overall structure of the skin.

Involucrin

IVL
The highly insoluble cornified envelope is formed by cross-linking of soluble precursor proteins such as loricrin, involucrin, envoplakin and periplakin.
In binding the protein loricrin, involucrin contributes to the formation of a cell envelope that protects corneocytes in the skin.

Stratum granulosum

granular layerGranular layer of skingranulosum
From the site of production, lamellar bodies migrate to the top of the stratum granulosum and then into the intercellular domain of the stratum corneum to extrude their contents, which are predominantly lipids.
Concomitantly, cells lose their nuclei and organelles causing the granular cells to become non-viable corneocytes in the stratum corneum.

Cellular differentiation

differentiationcell differentiationdifferentiate
Corneocytes are terminally differentiated keratinocytes and compose most if not all of the stratum corneum, the outermost part of the epidermis.

Skin

cutaneousskin cellanimal skin
They are regularly replaced through desquamation and renewal from lower epidermal layers, making them an essential part of the skin barrier property. Keratinocytes in the stratum basale of the epidermis will multiply through cell division and migrate toward the skin surface.

Cell nucleus

nucleusnucleinuclear
Corneocytes are keratinocytes without nuclei and cytoplasmic organelles.

Cytoplasm

cytoplasmiccytosolicintracytoplasmic
Corneocytes are keratinocytes without nuclei and cytoplasmic organelles.

Organelle

organellescell organellescell organelle
Corneocytes are keratinocytes without nuclei and cytoplasmic organelles.

Cell membrane

plasma membranemembranecell membranes
They contain a highly insoluble cornified envelope within the plasma membrane, and lipids (fatty acids, sterols and ceramides) released from lamellar bodies within the epidermis.

Lipid

lipidsglycerolipidfat
From the site of production, lamellar bodies migrate to the top of the stratum granulosum and then into the intercellular domain of the stratum corneum to extrude their contents, which are predominantly lipids. They contain a highly insoluble cornified envelope within the plasma membrane, and lipids (fatty acids, sterols and ceramides) released from lamellar bodies within the epidermis.

Sterol

sterolssterylzoosterol
They contain a highly insoluble cornified envelope within the plasma membrane, and lipids (fatty acids, sterols and ceramides) released from lamellar bodies within the epidermis.

Lamellar bodies

Lamellar granulesextracellular lipid lamellaemultilamellar bodies
They contain a highly insoluble cornified envelope within the plasma membrane, and lipids (fatty acids, sterols and ceramides) released from lamellar bodies within the epidermis.

Microorganism

microorganismsmicrobemicrobes
At the same time, as those loosened junctions encounter more hydration, they will expand and connect together, forming potential entry pores for microorganisms.

Stratum basale

basal layerbasal cellsStratum germinativum
Keratinocytes in the stratum basale of the epidermis will multiply through cell division and migrate toward the skin surface.

Cell division

divisiondaughter cellcellular division
Keratinocytes in the stratum basale of the epidermis will multiply through cell division and migrate toward the skin surface.

Latin

Latin languageLat.la
Corneocytes, also referred to as squames (from Latin squama, meaning a “thin flake” or “scales”) are terminally differentiated, anucleated cells of keratinocyte lineage that constitute the majority of stratum corneum, the outermost layer of the epidermis.

Intermediate filament

intermediate filamentsdesmosome-keratinfilament
Major constituents of corneocytes are keratin intermediate filaments organized in parallel bundles to form a matrix to give rigidity to the overall structure of the skin.

Ultraviolet

UVultraviolet lightultraviolet radiation
Size of a corneocyte is approximately 30-50 µm in diameter and 1 µm thick, and the average area of corneocytes at the surface of the skin reaches approximately 1000 µm 2, but may vary according to anatomical location, age and external environmental conditions such as ultraviolet (UV) irradiation. For example, corneocytes act as UV barrier by reflecting the scattered UV radiation, protecting cells inside the body from apoptosis and DNA damage.

Apoptosis

apoptoticprogrammed cell deathcell death
For example, corneocytes act as UV barrier by reflecting the scattered UV radiation, protecting cells inside the body from apoptosis and DNA damage.

DNA

deoxyribonucleic aciddouble-stranded DNAdsDNA
For example, corneocytes act as UV barrier by reflecting the scattered UV radiation, protecting cells inside the body from apoptosis and DNA damage.

Molecule

molecularmoleculesmolecular structure
Corneocytes contain small molecules called natural moisturizing factors, which absorb small amounts of water into the corneocytes thereby hydrating the skin.