Which chamber has the thickest wall (2-3x bigger) and why?

Which chamber has the thickest wall (2-3x bigger) and why?

• A. Left ventricle; it has to pump blood out of the heart to the entire body
• B. Right ventricle; it has to pump blood to the lungs
• C. Left atrium; it receives oxygenated blood from the lungs
• D. Right atrium; it receives venous blood

Answer: (A)

Chamber wall thickness reflects the force it must generate. The left ventricle must propel blood through the entire body against high systemic resistance, so its muscular wall is the thickest—roughly two to three times thicker than the right ventricle. This powerful wall provides the strong contractions needed to maintain systemic blood pressure. The right ventricle pumps to the lungs where pressures are much lower, so its wall is thinner. The atria collect blood at low pressure, yielding the thinnest walls. Therefore, the left ventricle has the thickest wall.

Chamber wall thickness reflects the force it must generate. The left ventricle must propel blood through the entire body against high systemic resistance, so its muscular wall is the thickest—roughly two to three times thicker than the right ventricle. This powerful wall provides the strong contractions needed to maintain systemic blood pressure. The right ventricle pumps to the lungs where pressures are much lower, so its wall is thinner. The atria collect blood at low pressure, yielding the thinnest walls. Therefore, the left ventricle has the thickest wall.