Question

The ventricles have thick muscular walls whereas the auricles have thin walls. Why do you think thick muscular walls are necessary in the ventricles and not in the auricles?

Answer 1

The ventricles have thicker muscular walls than the auricles. Blood flows in the ventricles under high pressure, as they have to pump blood to all body parts. The auricles have thin muscular walls. Blood flows into them under lower pressure, as they have to pump blood only to the ventricles.