Question

Cindy is taking 14 breaths per minute. Her vital capacity is 3000 mL, her total lung capacity is 4000 mL, and her tidal volume is 450 mL per breath. Calculate the following:

A. Cindy's total pulmonary ventilation (minute volume)
B. Cindy's alveolar ventilation rate

Answer 1

Cindy's total pulmonary ventilation is 6300 mL/minute and her alveolar ventilation rate is 4200 mL/minute.

Step-by-step explanation:

To calculate Cindy's total pulmonary ventilation (minute volume), we multiply her respiratory rate (14 breaths/minute) by her tidal volume (450 mL/breath). Therefore, Cindy's total pulmonary ventilation is 14 x 450 = 6300 mL/minute.

To calculate Cindy's alveolar ventilation rate, we subtract her dead space volume from her tidal volume and then multiply that by her respiratory rate. Dead space volume is the volume of air that stays in the conducting airways and doesn't reach the alveoli. Since the tidal volume is 450 mL per breath and the dead space volume is typically around 150 mL, Cindy's alveolar ventilation rate is (450 - 150) x 14 = 4200 mL/minute.