Contraction in Smooth Muscle Cells compared to Contraction in Skeletal Essay

Contraction in Smooth Muscle Cells comp bed to Contraction in Skeletal Muscle Cells - Essay ExampleIn this assignment, base on studies, a comparison has been drawn among the contractions of these cardinal types brawns at the cellular and molecular levels. in advance going into this discussion, contraction must be defined. Contraction is defined by activation of the muscle fibers with a demonstrable shortening of the muscle fibers2. The physiological events in relation to muscle contraction have been delineated in great detail, and they reveal that basically, with neural stimulation there occurs a series of molecular events initiated by increase in the cytosolic calcium concentration. In this assignment, these events will be looked at in a great detail to comp be these events between the striated and nonstriated muscles.Each skeletal muscle is made up of a considerable number of skeletal muscle fibers, which are thin cylindrical multinucleated cells of variable length, which i n turn are made up of myofibrils, which are bundles of filamentous structures running a longsighted the length of the fiber. While observing skeletal- or cardiac smooth muscle fibers through microscope, a series of light and dark bands perp sackicular to the long axis of the fiber are very conspicuous. Actually, each myofibril consists of repeating sarcomeres, and the alignment of these sarcomeres3 between attached myofibrils make its rise to these bands in the skeletal muscle. The structural plan of the myofibril is such that the sarcomeres are placed end to end, and this fundamental contracted unit is visible within skeletal and cardiac muscles. On the contrary, smooth muscle cells do not show a banding pattern. Actually, the arrangement of sarcomeres leads to the striated pattern in skeletal and cardiac fibers, and sarcomeres in turn comprise of alternate arrangements of numerous bass and thin filaments in the cytoplasm to give rise to roughly 1-2 micrometer cylindrical bundl es.Smooth muscles are abundant mainly in the intuitive organs, such as, gut, blood vessels, bladder, and uterus, and they are to serve a particular function. For example, smooth muscles present in the sphincters are designed to maintain a steady contraction for long periods of time and then rapidly slack up or in other muscles, they remain constantly activated. To suit these varied functions, the smooth muscles consists of sheets of many minor spindle-shaped cells linked together by junctional contacts. Although these serve as mechanical continuity between abutting spindles, actually, in places there are gap junctions that are designed to provide electrical continuity between cells. Each cell is uninucleated, shorter than striated muscles, and broader than a myofibril. Unlike striated muscle, no cross striations are visible, although they contain the same contractile protein filaments, actin and myosin. It is important to note that their arrangement is ir fixture in a loose latt ice unlike the regular arrangement of skeletal and smooth muscles. Myosin has been termed as a molecular motor. This consists of two heavy chains and two pairs of light chains. The two terminal ends of the heavy chains create a coil that aggregate in the cell to create the basic unit of a thick filament. The remainder of this molecule juts outward from the thick filament creating the cross-bridge. Thus, these polypeptides combine