Question: 7. how do the walls of the atria compare with the walls of the ventricles and why are they different?
Answer: The ventricles of the heart have thicker 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.