Desquamation

Desquamation (from Latin squama-scale), the shedding or peeling of cells from a surface. D. as a constant phenomenon is observed, for example, on the surface of the skin, where the peeling of cells of the keratinized epithelium (scales) occurs. Physiological D. of the epithelium can also be found during secretory processes in certain glandular organs (for example, in the mammary gland at the end of the lactation period). As a pathological phenomenon, D. is observed in inflammation of mucous membranes and hollow organs, for example, in the lungs, when due to tissue damage or other factor, intercellular connections are disrupted and the epithelium sheds. Desquamated cells usually die, but often remain viable and can even exhibit phagocytic and proliferative activity (for example, vascular endothelium, alveolar epithelium of the lungs). Inflammatory processes in which abundant D. of the covering epithelium occurs, which mixes with the exudate, are called desquamative (see Inflammation). D. can also occur depending on postmortem maceration, which is often observed in histological studies of postmortem material, for example, D. of the endothelium in blood vessels, etc.