(Solved): 17. The fint energy source used to regenerate ATP 2. when mueles are extremely active is: A fatty a ...

17. The fint energy source used to regenerate ATP 2. when mueles are extremely active is: A fatty acids C. creatine phosphate B. glucose D. pyruvic acid 18. ATP directly powers: A. exocytosis of synaptic vesicles in the axon terminal B. sodium influx at the sarcolemma C calcium release into the sarcoplasm D. recocking of the myosin head 19. After vigorous exercise: A. lactic acid is formed 2 2 B. lactic acid is reconverted to pyruvic acid C. ATP formation requires creatine phosphate D. muscle cells utilize glycogen reserves 20. Factors affecting the force of contraction include: A number of motor units stimulated B. cross-sectional area of the muscle/muscle fibers C. load D. degree of muscle stretch prior to the contraction 21. When the velocity of contraction is zero, the contraction is: C. greater than the load B. equal to the load D. isometric A strongest 22. Which of these bands or lines does not narrow when a skeletal muscle fiber contracts? A. H zone C. I band B. A band D. M line 23. Characteristics of red, but not white, muscle are: A. abundant mitochondria B. richly vascularized C. fast contraction D. slow to fatigue 200