Each smooth muscle cell (or muscle fiber) is just a few microns in diameter but may be two hundred microns long. The nucleus is also elongated, often cigar-shaped. In histologic sections, the full length of smooth muscle nuclei is only apparent when the plane of section is aligned with the long axis of the cells.
http://www.siumed.edu/~dking2/ssb/smoothm.htm
Smooth muscle: Along with skeletal and cardiac muscle, one of the types of muscle tissue in the body. Smooth muscle generally forms the supporting tissue of blood vessels and hollow internal organs, such as the stomach, intestine, and bladder. It is considered smooth because it does not have the microscopic lines (the striations) seen in the other two types of muscle.
http://www.medicinenet.com/script/main/art.asp?articlekey=5514
Structure of the smooth musculature. The smooth muscle cell is 3-10 µm thick and 20-200 µm long. The cytoplasm is homogeneously eosinophilic and consists mainly of myofilaments. The nucleus is located in the center and takes a cigar-like shape during contraction.
https://www.kenhub.com/en/library/anatomy/smooth-musculature
Functionally one differentiates between the single-unit and multi-unit type. The smooth muscle cells of the single-unit type are electrically connected by gap junctions and contract uniformly. This type of cells is found in the wall of internal organs and blood vessels (visceral smooth musculature). The multi-unit smooth cells are independent from each other and therefore need to be innervated individually allowing a more precise muscle control.
https://www.kenhub.com/en/library/anatomy/smooth-musculature
The cell membrane forms small pouch-like invaginations into the cytoplasm (caveolae) which are functionally equivalent to the T-tubules of the skeletal musculature. The smooth muscle cells are anchored to the surrounding connective tissue by a basal lamina. The smooth muscle fibers group in branching bundles.
https://www.kenhub.com/en/library/anatomy/smooth-musculature
When cut in longitudinal section, smooth muscle nuclei appear very long and sometimes wiggly (due to contraction). In cross-sectioned smooth muscle, only a fraction of the fibers display nuclei. Recall that each smooth muscle fiber is a single cell, each with its own nucleus. In each such cell, the nucleus occupies only a small proportion of the cell's total length.
http://www.siumed.edu/~dking2/ssb/smoothm.htm
The S.R. of the smooth muscle cell does not contain enough calcium to maintain contraction for long periods of time. How calcium starts the contraction process in smooth muscle: If you'll recall from the discussion of the biochemistry of smooth muscle cells, troponin is not found in smooth muscle.
http://courses.kcumb.edu/physio/smoothmuscle/eccoupling.htm
Excitation-Contraction coupling & contraction in smooth muscle. Excitation-Contraction Coupling: Some of the most important differences between skeletal muscle and smooth muscle occur in excitation-contraction coupling. One element that is the same between the two forms of muscle is that calcium plays a starring role. Unfortunately, that is about the extent of the similarities.
http://courses.kcumb.edu/physio/smoothmuscle/eccoupling.htm
Smooth muscle is fundamentally different from skeletal muscle and cardiac muscle in terms of structure, function, regulation of contraction, and excitation-contraction coupling. Smooth muscle cells known as myocytes, have a fusiform shape and, like striated muscle, can tense and relax.
https://en.wikipedia.org/wiki/Smooth_muscle
Smooth muscle ((unlike skeletal muscle) consists of individual cells (leiomyocytes), each cell with its own nucleus. The function of smooth muscle also differs substantially from that of striated muscle. Neurotransmitter activitation of smooth muscle is fairly diffuse.
http://www.siumed.edu/~dking2/ssb/smoothm.htm
where is the smooth muscle
The smooth muscle is in the tissue of blood vessels and hollow internal organs such as the stomach, intestine, and bladder. Smooth muscle generally found in the supporting tissue of blood vessels and hollow internal organs, such as the stomach, intestine, and bladder.