Complete the sentences describing the steps that occur during excitation-contraction coupling. Then put the steps in order. actin sarcomere tropomyosin troponin myosin heads transverse tubules Calcium ions sarcoplasmic reticulum lengthens calcium shortens Sodium ions As the electrical impulse reaches the __________, permeability of the cisternae to calcium increases. Thin (actin) filaments are pulled toward the center of the __________ by myosin cross-bridges. The muscle fiber __________ and contracts. __________ diffuse from the sarcoplasmic reticulum into the sarcoplasm. These ions bind to __________ molecules. After a muscle fiber is stimulated by a motor neuron, an electrical impulse travels along the sarcolemma and deep into the fiber via __________. Interaction between troponin and __________ results in exposure of binding sites on actin. Then, __________ bind to these sites.
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Excitation-contraction coupling in muscle occurs when an electrical impulse travels along the sarcolemma and deep into the fiber via interaction between troponin and Show more…
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