Which ventricle has a thicker wall and why?

Which ventricle has a thicker wall and why?

• A. Left ventricle, because it must generate higher pressure to pump blood through systemic circulation.
• B. Right ventricle, because it must generate higher pressure for pulmonary circulation.
• C. The left ventricle, due to a larger chamber volume.
• D. The right ventricle, because its wall is thicker to support respiration.

Answer: (A)

The main concept is that how thick a ventricle’s wall is depends on the pressure it must generate to move blood through its circuit. The left ventricle needs to pump blood into the systemic circulation, which has high resistance, so it generates a lot of pressure. To sustain that high pressure, its muscular wall is thick. The right ventricle, by contrast, pumps blood to the lungs where the pressure is much lower, so its wall is thinner and built for a gentler, more compliant pump. Chamber volume differences exist, but they’re not what primarily makes the left ventricle wall thicker. The option noting thicker wall for respiration is not correct, since respiration doesn’t require a thicker ventricular wall.

The main concept is that how thick a ventricle’s wall is depends on the pressure it must generate to move blood through its circuit. The left ventricle needs to pump blood into the systemic circulation, which has high resistance, so it generates a lot of pressure. To sustain that high pressure, its muscular wall is thick.

The right ventricle, by contrast, pumps blood to the lungs where the pressure is much lower, so its wall is thinner and built for a gentler, more compliant pump. Chamber volume differences exist, but they’re not what primarily makes the left ventricle wall thicker.

The option noting thicker wall for respiration is not correct, since respiration doesn’t require a thicker ventricular wall.