[noun] A fibroblast is the skin cell responsible for synthesising the parts of the dermis – the extracellular fibres (collagen and elastin) and matrix (hyaluronic acid). Skin ageing causes a decrease in fibroblast function and, as a result, in the production of the elements fibroblasts manufacture. Skin tends to become thinner, less supple, less plump, while wrinkles appear.