Fibroblasts are cells that make the structural fibers and ground substance of connective tissue. Fibroblasts have a branched cytoplasm surrounding an elliptical, speckled nucleus having 1 or 2 nucleoli. Fibroblasts make collagens, glycosaminoglycans, reticular and elastic fibers, and glycoproteins found in the extracellular matrix. In growing individuals fibroblasts are dividing and synthesizing ground substance. Tissue damage stimulates fibrocytes and induces the mitosis of fibroblasts.