Question

the right atrioventricular valve regulates the opening between the _____ and the _____.

Explanation:

The right atrioventricular valve (tricuspid valve) is located between the right atrium and the right ventricle of the heart. It regulates blood flow between these two chambers, preventing backflow from the right ventricle to the right atrium.

Answer:

right atrium; right ventricle