vusices with the neurotransmitter : and (3) the 7 Excitation contraction coupling refers to e action potential of a neuron triggering the release of neurotransmitters from synaptic vesicles the relationship between length of the sarcomere and the tension generated c the siding of thick and thin filaments past one another the relationship between excitation at the sarcolemma and release of calcium ions from the terminal cisternae of the sarcoplasmic reticulum er the following events of skeletal muscle contraction in the proper order, with number 1 for the first ev and number 6 for the last event. A power stroke occurs as myosin moves into its, relaxed position and puls the thin filament toward the M line Calcium ions bind to troponin, which pulls tropomyosin away from act ATP breaks the actin-myosin attachment, after which ATP is hydrolyzed and myosin is recocked The myosin head binds to an actin subunit The energy from ATP hydrolysis "cocks" the myosin head into an upright position. The terminal cisternae of the sarcoplasmic reticulum release calcium ions into the sarcoplasm. 9 Maximal tension in a skeletal muscle contraction is generated a when the sarcomeres are at about 100 to 120 percent of their natural length. b. when the muscle fiber is stretched before the contraction. c when the muscle fiber is shortened before the contraction, and there is a maximal zone of overlap. d. when the sarcoplasmic reticulum releases fewer calcium ions.
