A reduction in extracellular Ca²⁺ levels would lead to A) increased force of cardiac muscle contraction due to increased interactions between actin and myosin. B) decreased force of cardiac muscle contraction due to a lack of release of Ca²⁺ from the sarcoplasmic reticulum. C) heart block due to depolarization of the sarcolemma. D) heart block due to hyperpolarization of the sarcolemma.

Question

Quizplus · Accepted Answer

Decreased extracellular calcium levels lead to a reduced influx of calcium into cardiac muscle cells during action potentials, which in turn results in a decreased release of calcium from the sarcoplasmic reticulum. This reduced release of calcium diminishes the interaction between actin and myosin, ultimately decreasing the force of cardiac muscle contraction.

A Reduction in Extracellular Ca2+ Levels Would Lead to

A Reduction in Extracellular Ca²⁺ Levels Would Lead to