Pulmonary artery cell. Fluorescence deconvolution micrograph of a cultured cell from a pulmonary artery. The cell nucleus, which contains the cell's genetic information, is blue. Actin protein filaments, which make up part of the cytoskeleton, are green. The cytoskeleton maintains the cell's shape, allows some cellular mobility and is involved in intracellular transport. Mitochondria, which produce energy for the cell, are red.