Skeletal Muscle Contraction MCQ Quiz | Nerve-Muscle

Welcome, MBBS students! This quiz is designed to rigorously test your understanding of the intricate process of Skeletal Muscle Contraction, a cornerstone topic in Nerve-Muscle Physiology. You will face 25 multiple-choice questions covering everything from the molecular machinery of sarcomeres, the roles of calcium and ATP, to the events at the neuromuscular junction and excitation-contraction coupling. This is an excellent opportunity to reinforce your knowledge and identify areas for further study. After submitting your answers, you’ll receive your score and see the correct responses highlighted. For your revision, you can also download all the questions along with their correct answers in a convenient PDF format. Good luck, and may your synaptic transmissions be swift!

1. In the sliding filament model of muscle contraction, which of the following bands or zones shortens?

2. The binding of which molecule to troponin C initiates the conformational change that exposes the myosin-binding sites on actin?

3. What is the primary function of the sarcoplasmic reticulum (SR) in skeletal muscle?

4. Rigor mortis occurs after death because of the depletion of which molecule?

5. The release of acetylcholine at the neuromuscular junction directly causes:

6. In excitation-contraction coupling, the action potential travels down the T-tubules and activates which receptor?

7. The power stroke of the myosin head is immediately preceded by:

8. Which of the following describes an isometric contraction?

9. A single motor neuron and all the muscle fibers it innervates is called a:

10. What is the role of acetylcholinesterase at the neuromuscular junction?

11. Type I (slow-twitch) muscle fibers are characterized by all of the following EXCEPT:

12. The immediate source of energy for the first few seconds of intense muscle contraction is:

13. The protein that anchors thick filaments to the Z-disc is:

14. Which part of the myosin molecule has ATPase activity?

15. The phenomenon where repeated stimulation of a muscle fiber leads to a sustained contraction is known as:

16. The end-plate potential (EPP) is a graded potential that, if it reaches threshold, will trigger:

17. Which component of the thin filament directly blocks the myosin-binding sites on G-actin in a relaxed muscle?

18. The process of increasing the number of active motor units to produce a stronger muscle contraction is called:

19. The H-zone of a sarcomere contains:

20. What is the main function of T-tubules (transverse tubules)?

21. The detachment of the myosin head from the actin filament is directly caused by:

22. Which of these events occurs FIRST in the sequence of muscle contraction?

23. In a fully contracted muscle, which of the following is most likely to disappear?

24. Malignant hyperthermia is a life-threatening condition triggered by certain anesthetics, leading to excessive Ca2+ release from the SR. This is often due to a mutation in the:

25. The resting membrane potential of a skeletal muscle fiber is primarily maintained by: