EM of smooth muscle in longitudinal section. The single nucleus is in the widest part of the cell and conforms to its shape. The juxtanuclear sarcoplasm contains a mixture of organelles, including Golgi complex (G), ribosomes, mitochondria (Mi), and centriole (C). Filaments make up the bulk of the sarcoplasm and are densely packed and oriented parallel to the long axis of a cell. Dense bodies (DB) are regularly distributed along the perimeter of the cell and are dispersed throughout the sarcoplasm. The surrounding connective tissue (CT), some of which is produced by the smooth muscle cell, contains collagen and elastic fibrils. 23,000×.