Quiz 7 The Muscular System

1. Skeletal Muscle Is Involuntary Is Striated Is composed of short, branching cells Both B and C

2. Cardiac & Smooth muscle are similar because They are both found in the heart They are both involuntary They are both attached to bones of the skeleton They both have striations B and D

3. The Connective Tissue Layer Endomysium surrounds what structure? Myofilament Sarcomere Fascicle Muscle (cell) fiber The entire muscle

4. One Sarcomere Runs from M line to M line Runs from Z disc to Z disc Runs from the A band to the Z line Is only found within the H-band Is the entire length of a myofibril

5. Name the entire cylinder at the arrow. Endomysium Perimysium Myofibril Muscle fiber Fascicle

6. Name the region enclosed by the green bracket. A band H band Z line I band M zone 7. What does the green region contain? Thin filaments only Thick filaments only No thin or thick filaments Thick and thin filaments None of the above

8. Name the white connective tissue at the arrow Endomysium Epimysium Perimysium Myofibril Fascicle Muscle Fiber

9. What is the name of the skeletal muscle cell membrane? Sarcoplasmic reticulum Sarcoplasm Thick filament Myofilaments Sarcolemma

10. When Acetylcholine binds to Ach receptors on the muscle fiber, The muscle fiber becomes more permeable to chloride ions The muscle fiber becomes more permeable to sodium The muscle fiber stays polarized The muscle fiber becomes more permeable to calcium None of the above

11. The function of a T-tubule is to, Generate the action potential To stop the action potential To release calcium Release enzymes to destroy acetylcholine Transmit the action potential deep into the muscle fiber

12. Depolarization of the skeletal muscle fiber is due to: Ca2+ ions exiting the cell Na+ (sodium) ions exiting the cell Na+ ions entering the cell Acetylcholine entering the cell

13. When intracellular calcium levels are low (negligible), Myosin heads can bind actin Myosin heads cannot bind to actin The muscle is fully contracted None of the above

14. The neuromuscular junction includes: The axon terminal, synaptic vesicles, and synaptic cleft The axon of the motor neuron, the axon terminal and Ach The axon terminal, synaptic cleft and folds of sarcolemma The synaptic cleft, T-tubules and folds of sarcolemma None of the above

15. In which of the following structures/regions is Acetylcholine (Ach) stored? Sarcolemma Sarcoplasmic reticulum T- tubule Synaptic vesicles Synaptic cleft