The site where myosin heads to action in skeletal muscles are covered by: (A) Tropomyosin, (B) Troponin o, (C) Calcium, (D) None of the above
Answer is A. In resting muscle, troponin I is bound to actin and tropomyosin covers the site where myosin head interacts with actin. Ref: Ganong&;s Review of medical physiology;25th edition; pg: 104.