What is the net volume of fresh air that enters the alveoli each minute, assuming that the breathing rate is 10 breaths/min, the tidal volume is 800 ml/breath, and the nonalveolar respiratory system volume (dead space) is 150 ml?

6,500 mL

Explanation:

We are asked to find the total volume of air that effectively entered to the alveoli in one minute so that oxygen could be exchanged for carbon dioxide and leave the body through exhalation.

The problem says that the normal breathing rate is 10 breaths per minute, and for each breathe it takes 800 mL of air. But not all air enters the alveoli because it says there are 150 mL that are not effectively used by the alveoli. Therefore, the net amount of air used in each breathe is 800 ml - 150mL, giving us a total amount of 650 mL of air.

Now that we have the net amount of air for each breathe, we have to multiply it by the total breaths a body makes in one minute. In this case, the breathing rate is 10 breaths/min.

So, to obtain the final answer we just need to multiply the amount of net air per breathe (650 mL) times the number of breathes in one minute (10 breathes); that is 650 mL/breath x 10 breaths and gives us 6,500 mL.