What cell is the most abundant in the epidermis?
1 Answer
Keratinocytes are the most abundant cells in the epidermis.
Explanation:
The epidermis consists of four or five layers of cells.
It is made up of 95% keratinocytes, cells that manufacture and store keratin.
Keratin is the protein that gives hair, nails, and skin their hardness and water-resistant properties.
Epidermal layers
(From courses.lumenlearning.com)
The stratum basale (basal layer)
The stratum basale is the deepest epidermal layer.
It consists of a single layer of the youngest, rapidly-dividing keratinocytes.
The stratum spinosum (spiny layer)
The stratum spinosum consists of eight to 10 layers of keratinocytes.
The keratinocytes in this layer begin the synthesis of keratin.
The stratum granulosum (granular layer)
The stratum granulosum consists of three to five layers of cells.
They are flatter, have thickened cell membranes.
They generate large amounts of keratin, which is fibrous, and keratohyalin, which accumulates as layered granules within the cells.
These two proteins give the layer its grainy appearance.
The nuclei and other cell organelles disintegrate as the cells die, leaving behind the keratin, keratohyalin, and cell membranes.
The stratum lucidum (clear layer)
The stratum lucidum is a thin, transparent band consisting of a few rows of flat, dead keratinocytes.
It is found only in the palms, soles, and digits.
These cells are densely packed with eleidin, a clear lipid-rich protein derived from keratohyalin, which gives these cells their transparent appearance and provides a barrier to water.
The stratum corneum (horny layer)
The stratum corneum consists of 15 to 30 layers of dead, keratinized cells.
Its functions include waterproofing, protection from abrasion and biological and chemical assaults.
