Which is TRUE about the comparison of excitation-contraction coupling in cardiac muscle with that in skeletal muscle?
A. Extracellular Ca2+ plays a major role in cardiac but not skeletal muscle.
B. The mechanism for Ca2+ release from the sarcoplasmic reticulum is the same in both types of muscle.
C. Intracellular Ca2+ stores are necessary for contraction in skeletal muscle, but not in cardiac muscle.
D. Troponin sites are completely saturated immediately after Ca2+ release in both types of muscle.
E. There is no net change in total intracellular Ca2+ concentration in either muscle.
Answer: A
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Fill in the blank(s) with correct word
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