An electrical impulse results in which action to pump blood and produce a pulse?

An electrical impulse results in which action to pump blood and produce a pulse?

• A. Mechanical contraction
• B. Electrical synchronization
• C. Diastolic relaxation
• D. Venous return

Answer: (A)

The impulse tested here triggers excitation-contraction coupling in the heart. When the electrical signal reaches the cardiac muscle, it causes calcium to be released inside the cells, allowing the fibers to contract. This mechanical contraction of the ventricles ejects blood into the aorta and pulmonary artery, creating the pulse. The other ideas describe things that don’t directly produce the pulse: electrical synchronization is about coordinating the timing of impulses, not the actual pumping action; diastolic relaxation is the heart’s filling phase after contraction; venous return is the blood flowing back to the heart, not the immediate result of the impulse.

The impulse tested here triggers excitation-contraction coupling in the heart. When the electrical signal reaches the cardiac muscle, it causes calcium to be released inside the cells, allowing the fibers to contract. This mechanical contraction of the ventricles ejects blood into the aorta and pulmonary artery, creating the pulse.

The other ideas describe things that don’t directly produce the pulse: electrical synchronization is about coordinating the timing of impulses, not the actual pumping action; diastolic relaxation is the heart’s filling phase after contraction; venous return is the blood flowing back to the heart, not the immediate result of the impulse.