Question

please answer within 5 mins!

46) Which of the following is referred to as the period of lost excitability in skeletal muscle fibers? a) refractory period b) contraction period c) latent period d) relaxation period e) wave summation 47) Increasing the number of active motor units within a skeletal muscle is called a) wave summation. b) fused tetanus. c) motor unit recruitment. d) muscle tone. e) flaccidity. 48) Which of the following microscopic structures is only found in the cardiac muscle tissue? a) myosin b) tropomyosin c) sarcomeres d) intercalated discs e) striations 49) Which of the following types of muscle tissue contract when excited by their own muscle fibers? a) cardiac muscle b) slow twitch oxidative skeletal muscle c) multi-unit smooth muscle d) fast twitch glycolytic skeletal muscle e) All of these choices are correct. autorhythmic 50) Smooth muscle tone is maintained by the prolonged presence of a) ATP b) calcium ions c) phosphate ions d) myoglobin e) None of these choices. in the muscle cell's cytosol? 51) Which of the following statements does NOT accurately describe aerobic cellular respiration in skeletal muscles? a) Pyruvic acid generated by glycolysis enters the mitochondria. b) 02 is essential.

Answer 1

ANSWER :

46) During the refractory period a skeletal muscle is unable to respond a stimulus and cannot generate an action potential to initiate muscle contraction but very small in skeletal muscle (1-2 ms).

47) To increase the force of contraction, all the motor units of a skeletal muscle begin to activate via motor unit recruitment.

48) Intercalated discs are only present in the cardiac muscles of the heart and connect the cardiomyocytes to perform synchronised contraction of cardiac tissue.

49) Only cardiac muscles have ability to contract self when excited via autorhythmic muscle fibres present at the SA (sinoatrial) node of the heart.