The process of ageing reflected by histological changes in the skin.

Structural and functional alterations, as well as changes occurring in the aspect of the skin during the ageing process, are due to some complex mechanisms, determined by intrinsic and extrinsic factors, which act synergistically. This study aims to analyze the histological changes of collagen and elastic fibers and of skin vasculature that occur in time, during the process of ageing. Fragments of skin have been collected from subjects of both sexes and of different ages, totaling 121 samples from different body regions. The following stains were used: Modified Goldner's Masson trichrome, Ferric Orcein-Hematoxylin and the combined stains Orcein-Goldner's trichrome. As the process of ageing advances, collagen fibers become thinner and change their aspect; at advanced age, the lysis of collagen fibers and their thickening in the deep dermis is present, as they become more fibrous. Elastic fibers show the tendency of fragmentation at more advanced age, gradually change their tinctorial affinity and reduce in amount; in the deep dermis, they tend to thicken progressively, in the presence of discrete elastolysis processes that evolve steadily and irreversibly. Thus, processes of elastic fibers degeneration and lysis run faster by comparison with those of collagen fibers degeneration. With ageing, a progressive reduction of dermis vasculature is present, due to a reduction in the number and size of vascular vessels, which is in its turn associated with the progressive alterations of vascular walls components, changes that advance until the function of the vessel ceases.