Question

why are ventricles thick walled and mascular?

Answer 1

The ventricles of the heart havethicker muscular walls than the atria. This is because blood is pumped out of the heart at greater pressure from these chambers compared to the atria. The left ventricle also has a thicker muscular wall than the right ventricle, as seen in the adjacent image.
HOPE IT HELPS
PLZ MARK AS BRAINLIEST

Answer 2

coz they have to face a direct pressure becoz of the first heart beat which forces artria to push the blood to ventricles.