Question

during the isovolumetric contraction period of the cardiac cycle. multiple choice pressure in the ventricles decreases. av and semilunar valves are closed. ventricular volume increases. the atria are contracted. blood is pumped into the large arteries.

Explanation:

During isovolumetric contraction, the ventricles start to contract. The AV (atrioventricular) valves close to prevent back - flow into the atria, and the semilunar valves are not yet open as ventricular pressure has not exceeded arterial pressure. So, both AV and semilunar valves are closed. Ventricular pressure increases, volume remains constant (hence isovolumetric), atria are relaxed, and no blood is pumped into large arteries yet.

Answer:

B. AV and semilunar valves are closed.