green and blue light illustration

Fibroblast. A confocal microscopy image of a fibroblast showing the nucleus (blue), mitochondria (red), and actin cytoskeleton (green). As is evident from their large number of mitochondria, fibroblasts are very metabolically active, continuously synthesizing elements of the extracellular matrix and collagen. Tissue damage is a major trigger for the activation of fibroblasts from fibrocytes, and so fibroblasts play an important role in wound healing.