___ Guards the opening of the left auricle to the left ventricle.
Heart valves:
Bicuspid valve
How do you account for the following differences? (a) The left ventricle has thicker walls than the right ventricle. (b) The walls of the right ventricle are thicker than those of the right auricle.
The opening between left auricle and left ventricle is guarded by________