Light micrograph of the center of a recent fibrous scar showing fibroblasts, capillaries, collagen, and lymphoid/macrophagic cells. Fibroblasts are flat, elongated, undifferentiated cells in connective tissue that give rise to various precursor cells that form the fibrous, binding, and supporting tissue of the body. Fibroblasts can become chondroblasts, collagenoblasts, or osteoblasts.