Question

In the truncus arteriosus of frog, synangium is separated from pylangium by which valve?

• A. Spiral valve
• B. Distal row of semilunar valves
• C. Proximal row of semilunar valves
• D. Secondary septum

Answer 1

The correct option is C Proximal row of semilunar valves

The walls of the truncus arteriosus are thick and muscular. At its anterior end, it divides into two trunks. The elongated undivided part is the pylangium, the terminal part common to the divergent trunks is the synangium. Three proximal semilunar valves separate the pylangium from the synangium.