New skin is made in the lower layers of the epidermis through a continuous process of cell production and migration.
Here's a breakdown of the process:
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Cell Production: New skin cells, called keratinocytes, are created in the basal layer (the deepest layer) of the epidermis. These cells are constantly dividing.
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Upward Migration: As new cells are generated, they push older cells upwards towards the skin's surface.
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Differentiation: During this upward journey, keratinocytes undergo a process called differentiation. They flatten, lose their nuclei, and become filled with keratin, a tough, fibrous protein.
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Surface Layer Formation: Eventually, these flattened, keratin-filled cells reach the stratum corneum, the outermost layer of the epidermis. These cells are now essentially dead and form a protective barrier.
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Shedding: These dead skin cells are continuously shed from the surface, making way for new cells that have migrated upwards. This process of renewal takes approximately four weeks.
In essence, your skin is constantly renewing itself from the bottom up. New cells are born, they mature and migrate to the surface, and then they are shed, all within a relatively short period.
