12 Steps to Muscle Contraction

(electrical current) across the sarcolemma. Action potential travels across the sarcolemma and down the . T-tubules. which triggers the . sarcoplasmic reticulum SR. to release Ca+. As Ca+ levels rise, Ca+ ions bind with . Troponin. which removes the blocking action of . Tropomyosin. from the . Actin binding sites. Myosin is now ready to bind ... ................
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