Viva Question and Answers Related to Muscles and Neuromuscular junction

Here are 25 viva questions and answers related to muscles and the neuromuscular junction:

1. What is the primary function of muscles in the body?
   • Muscles are responsible for movement, stability, and maintaining posture.
2. Define the term “muscle fiber.”
   • A muscle fiber is a single, elongated cell that makes up a skeletal muscle.
3. What is the neuromuscular junction?
   • The neuromuscular junction is the point of communication between a nerve ending and a muscle fiber, where the nerve signals the muscle to contract.
4. What neurotransmitter is released at the neuromuscular junction?
   • Acetylcholine (ACh).
5. Explain the process of muscle contraction.
   • Muscle contraction is initiated by the release of neurotransmitters (ACh) at the neuromuscular junction, leading to the generation of an action potential and the sliding of actin and myosin filaments.
6. What is a motor unit?
   • A motor unit consists of a motor neuron and all the muscle fibers it innervates.
7. Differentiate between isotonic and isometric muscle contractions.
   • Isotonic contractions involve muscle length changes, while isometric contractions occur without a change in muscle length.
8. What is the role of ATP in muscle contraction?
   • ATP provides the energy required for muscle contraction and relaxation.
9. Explain the sliding filament theory.
   • The sliding filament theory describes how actin and myosin filaments slide past each other during muscle contraction, resulting in muscle shortening.
10. What is muscle fatigue, and what causes it?
    • Muscle fatigue is the decline in muscle performance due to factors like depletion of ATP, accumulation of lactic acid, and decreased calcium availability. Viva Question and Answers Related to Carbohydrate Metabolism
11. Describe the structure of a sarcomere.
    • A sarcomere is the basic functional unit of a muscle, consisting of overlapping actin and myosin filaments between Z-lines.
12. What is the role of calcium ions in muscle contraction?
    • Calcium ions trigger the binding of myosin to actin during muscle contraction.
13. How does the nervous system control muscle contraction?
    • The nervous system controls muscle contraction through motor neurons and the release of neurotransmitters at the neuromuscular junction.
14. What are the three types of muscles in the human body?
    • Skeletal, smooth, and cardiac muscles.
15. Explain the difference between voluntary and involuntary muscle contractions.
    • Voluntary contractions are consciously controlled, while involuntary contractions occur without conscious control.
16. What is the role of the sarcoplasmic reticulum in muscle contraction?
    • The sarcoplasmic reticulum stores and releases calcium ions required for muscle contraction.
17. How does muscle hypertrophy occur?
    • Muscle hypertrophy occurs through an increase in the size of individual muscle fibers, often in response to resistance training.
18. What is a twitch in the context of muscle contraction?
    • A twitch is a brief, involuntary contraction of a small number of muscle fibers.
19. Explain the concept of the “all-or-none” response in muscle contraction.
    • The all-or-none response means that a muscle fiber contracts completely when it is stimulated adequately but does not contract at all when the stimulus is insufficient. Viva Questions and Answers Related to Tongue thrust Habit
20. What is the role of troponin and tropomyosin in muscle contraction?
    • Troponin and tropomyosin regulate the interaction between actin and myosin by controlling access to the binding sites on actin.
21. How does acetylcholinesterase contribute to muscle relaxation?
    • Acetylcholinesterase breaks down acetylcholine, preventing continuous stimulation and allowing for muscle relaxation.
22. What is the difference between concentric and eccentric muscle contractions?
    • Concentric contractions involve muscle shortening, while eccentric contractions involve muscle lengthening.
23. What is the significance of the H-zone and I-band in a sarcomere?
    • The H-zone is where only myosin filaments are present, and the I-band contains only actin filaments; changes in these regions are crucial for muscle contraction.
24. How do neuromuscular diseases, like myasthenia gravis, affect muscle function?
    • Neuromuscular diseases can impair the communication between nerves and muscles, leading to muscle weakness and fatigue.
25. Explain the role of ATPase in muscle contraction.
    • ATPase is an enzyme that hydrolyzes ATP to provide the energy needed for the cross-bridge cycling between actin and myosin during muscle contraction.