BIOB32H3 Lecture Notes - Electron Microscope, Myocyte, Sarcomere
8 May 2012
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Document Summary
The muscle length-tension relationship is the relationship between the length of the fiber and the force that the fiber produces at that length. This length is referring to the length of an isolated fiber and is dependent upon the position of the actin and myosin filaments in the sarcomeres. The sarcomere is the contractile unit of a muscle fiber, and a muscle fiber is composed of thousands of sarcomeres. The actin and myosin filaments are proteins that create cross bridges and are responsible for the contractions, or shortening, of a fiber (see figures). When an isolated muscle fiber is stretched to the point of minimal overlap of actin and myosin and then stimulated by an electrode to contract , the force of contraction measured is minimal. When an isolated muscle fiber is stimulated to contract when there is optimal overlap of actin and myosin the force produced is maximal.
