Question: are semilunar valves in veins?
Answer: These valves permit blood to be forced into the arteries, but prevent backflow from the arteries into the ventricles. Semilunar valves do not have chordae tendineae, and resemble valves in veins, rather than atrioventricular valves. The semilunar valves of both arterial outlets are formed at the level of the truncus.