By Michael Weiss. âSectarian violence in Syria raises fears,â screamed the headline of a Washington Post article on the murder Tuesday of 16 Syrians in the city of Homs, which lies 100 miles north of Damascus.
Multi-unit smooth muscle is found in the walls of large blood vessels, in large airways in the lungs, in the muscle of the eye that adjusts the lens and alters the size of the pupil, and in the base of hair follicles in the skin. SINGLE-UNIT muscle is the more common. It is commonly called visceral muscle and is found in the walls of hollow organs (e.g. digestive, reproductive, urinary system). Sheets of single-unit muscle fibres contract as a single unit as they are electrically linked by gap junctions (like cardiac muscle). This permits coordinated contraction of a whole organ. Single unit smooth muscle is self-excitable as clusters of specialised smooth muscle cells display spontaneous electrical activity.
Structure of the smooth musculature. The smooth muscle cell is 3-10 Âµm thick and 20-200 Âµm 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.unctionally 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).