Physiology Regarding lung volumes, which of the following is true: March 2009 A Functional residual capacity accounts for 75% of total lung capacity B Residual volume keeps alveoli inflated between breaths C Vital capacity increases in elderly D Residual volume is about 500 ml 💡 Explanation Regarding lung volumes, which of the following is true: March 2009 ✓ Correct Answer: B. Residual volume keeps alveoli inflated between breaths