Final answer:
It is true that ventricles are the thicker, more powerful chambers of the heart responsible for pumping blood to the lungs and body, with the left ventricle having a thicker muscle to overcome greater resistance in the systemic circuit.
Step-by-step explanation:
The statement that ventricles are the thicker, more powerful chambers of the heart and that they pump blood to the lungs and body is true. The human heart is divided into four chambers, with the ventricles serving as the primary pumping chambers. The muscle of the left ventricle is much thicker than that of the right ventricle due to the higher pressure needed to pump blood through the extensive systemic circuit to the rest of the body. In contrast, the right ventricle pumps blood to the lungs via the pulmonary circuit, which requires less pressure due to the shorter distance.