What is a typical effect on muscle contraction due to hyperpolarization?

What is a typical effect on muscle contraction due to hyperpolarization?

• A. Muscles contract more forcefully.
• B. Muscles become less responsive and fatigue more easily.
• C. Muscles contract more quickly.
• D. Muscles are unaffected.

Answer: (B)

Hyperpolarization makes the cell’s membrane potential more negative, moving it further from the threshold needed to trigger an action potential. In muscle fibers, fewer action potentials mean less calcium release for contraction, so the muscle is less responsive to stimuli. Repeated stimulation becomes harder to sustain because the next contraction is harder to initiate, leading to fatigue more easily. So the typical effect is that muscles are less responsive and tiring more quickly.

Hyperpolarization makes the cell’s membrane potential more negative, moving it further from the threshold needed to trigger an action potential. In muscle fibers, fewer action potentials mean less calcium release for contraction, so the muscle is less responsive to stimuli. Repeated stimulation becomes harder to sustain because the next contraction is harder to initiate, leading to fatigue more easily. So the typical effect is that muscles are less responsive and tiring more quickly.