During the Cardiac Cycle, the Aortic and Pulmonic Valves Close

question 19

Multiple Choice

During the cardiac cycle, the aortic and pulmonic valves close after the ventricles contract because the:

• A)papillary muscles relax, which allows the valves to close.
• B)chordae tendineae contract, which pulls the valves closed.
• C)reduced pressure in the ventricles creates a negative pressure, which pulls the valves closed.
• D)blood fills the cusps of the valves and causes the edges to merge, closing the valves.