Smooth muscle is non-striated, involuntary muscle found in many locations. Smooth muscle cells are spindle-shaped with a centrally located nucleus.
Longitudinal Section: in relaxed smooth muscle, the nuclei are elongated with rounded ends. When contracted, the nuclei spiral, kink, or twist. The cytoplasm is pink, non-striated and with little detail.
Cross-Section: individual cells vary in diameter depending on their location within the cell. Cross-sections through the middle of cells have centrally located nuclei, usually surrounded by an unstained region.