Biology - Body Fluids and Circulation Question with Solution | TestHub

The right atrioventricular aperture is guarded by the tricuspid valve.

The opening of the postcaval (inferior vena cava) into the right atrium is guarded by the Eustachian valve. The Thebesian valve guards the opening of the coronary sinus into the right atrium. Thus, the statement regarding the postcaval opening is incorrect.

The openings of the pulmonary veins into the left atrium lack valves.

The openings of the right and left ventricles into the pulmonary artery and the aorta respectively are guarded by semilunar valves.

Answer: The opening of the postcaval into the right atrium is guarded by a Thebesian valve.