Keratinisoituneet

Keratinisoituneet is a term used to describe cells or tissue that have undergone keratinization, a differentiation process in which cytoplasmic keratin proteins accumulate, the cell contents die, and a cornified, protective layer forms. In histology, keratinization results in keratin-rich cells that contribute to the barrier function of the epithelium.

Keratinization occurs mainly in stratified squamous epithelia, most notably the epidermis of the skin. In the skin, keratinocytes migrate from the basal layer through the granular layer to become corneocytes in the stratum corneum, forming a durable outer layer. Many mucosal surfaces are non-keratinized under normal conditions (for example, oral mucosa), but keratinization can occur in response to irritation, friction, or disease, leading to hyperkeratosis. Keratinisoituneet epithelium can thus indicate adaptive changes or pathology in various tissues.

In pathology, the presence of keratinized cells is a diagnostic feature in certain conditions. For example, well-differentiated squamous cell carcinomas often exhibit keratinization arranged into keratin pearls. Histological terms related to Keratinisoituneet include orthokeratosis (keratinization without nuclei in the outermost layer) and parakeratosis (retained nuclei in the keratinized layer). Assessing the degree and pattern of keratinization helps distinguish normal from abnormal epithelium and aids in disease characterization.