Which of the following statements is true?

1. Minute ventilation is the product of inspiratory volume and respiratory rate
2. Minute ventilation can be modified using medications
3. Minute ventilation is independent of individual variations in respiratory rate
4. Respiratory paralysis does not affect minute ventilation significantly.

Answer: The answer is ( b). Minute ventilation is the product of tidal volume and respiratory rate. Therefore medications which can change the tidal volume alter the minute ventilation. Respiratory paralysis makes the minute ventilation zero.