Which of the Following Statements Are True of the Valves

Multiple Choice

Which of the following statements are true of the valves of the heart (Select all that apply) ?

A) The pulmonary and aortic valves are important to prevent backflow of blood when the ventricles contract.
B) The right and left AV valves are important to prevent backflow of blood when the ventricles relax.
C) The pulmonary and aortic valves prevent backflow of blood from arteries to ventricles.
D) The edges of the semilunar valves are anchored by the chordae tendineae and papillary muscles.
E) The right and left AV valves prevent backflow of blood from atria to ventricles.
F) The valve openings are kept from stretching by the fibrous skeleton of the heart.