carbon dioxide dead space vital capacity trachea inhale oxygen exhale alveoli lungs bronchi

To do so, a certain volume of air is used to dilute the CO2 in the alveoli of the lungs by means of inhalation and exhalation. To maintain the pH balance in the blood, the lungs must be able to “blow off” the CO2 that is produced by the body. The CO2 combines with the water in the blood to form carbonic acid (which dissociates as hydrogen and bicarbonate ions).1 The change in the pH of the blood is sensed by the brain and serves as the trigger to stimulate breathing. Of these two processes, the exhalation of CO2 is actually the main driver of breathing. The lungs’ most important function is to facilitate gas exchange: supplying oxygen to the bloodstream and extracting and exhaling carbon dioxide (CO2).

Thus it is important that divers know what limitations to pulmonary function occur while diving. Lung conditions are among the most common reasons people fail diving medical examinations - and of course we depend on our lungs for survival. Diving imposes significant challenges to the respiratory system.

Carbon dioxide dead space vital capacity trachea inhale oxygen exhale alveoli lungs bronchi