Keratinocytes within hair follicles are the cells that produce hair.
Keratinocytes are specialized skin cells that produce keratin, a tough, fibrous protein that is the main structural component of hair. The process occurs within hair follicles, which are tube-like structures in the skin.
Here's a more detailed breakdown:
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Hair Follicles: Hair follicles are invaginations of the epidermis (outer layer of skin) into the dermis (deeper layer of skin).
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Keratinocytes and Keratinization: Within the hair follicle, keratinocytes divide and differentiate. As they mature, they fill with keratin. This process is called keratinization. Eventually, the keratinocytes die, leaving behind a hardened, keratinized structure – the hair shaft.
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Stem Cells: The process of hair growth relies on stem cells located in the hair follicle bulge. These stem cells divide and differentiate into keratinocytes, replenishing the cells that make up the hair shaft.
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Hair Growth Cycle: The hair follicle goes through cycles of growth (anagen), regression (catagen), and rest (telogen). During the anagen phase, keratinocytes are actively producing hair.
In summary, while hair itself is non-living, it is produced by living keratinocytes within the hair follicle through the process of keratinization. These keratinocytes originate from stem cells also located within the hair follicle.
