Keratinisoitumisessa

Keratinisoituminen, also known as keratinization, is a biological process that occurs in epithelial cells, particularly in the epidermis of the skin. It involves the synthesis and accumulation of keratin, a tough, fibrous protein, within the cells. As keratinocytes, the cells of the epidermis, move upwards from the basal layer, they undergo a series of programmed changes. This differentiation process results in the cells flattening, losing their organelles like the nucleus and mitochondria, and becoming filled with keratin.

This transformation is crucial for the formation of a protective barrier. The outermost layer of the epidermis, the stratum corneum, is composed entirely of these dead, keratinized cells, often referred to as corneocytes. These cells are tightly packed and joined by desmosomes, forming a robust barrier that protects the underlying tissues from mechanical stress, dehydration, and invasion by pathogens. The degree of keratinization can vary across different parts of the body, with thicker keratinized layers found in areas subjected to more friction, such as the soles of the feet and palms of the hands. This process is essential for the integrity and function of the skin and other keratinized structures like hair and nails.