I think they're referring to what we call "dead space" in respiratory physiology, which is the part of the respiratory tract that isn't involved in oxygenation (gas exchange). Our alveoli are the only structures in our lungs that are actually exchanging gases, everything else is considered dead space (e.g. trachea, bronchus) because there is no exchange happening there. We also call those parts of the airway the conducting airway, since all they do is move air (conduction), whereas the respiratory airway refers to the alveoli since it is involved in gas exchange (respiration).
Since giraffes have very long necks and thus longer conducting airways, it would be reasonable to assume that they have much more dead space than humans do, proportionally speaking of course.
Vexina1997 t1_j44andl wrote
Reply to comment by 4tehlulzez in How do giraffes breathe? by NimishApte
I think they're referring to what we call "dead space" in respiratory physiology, which is the part of the respiratory tract that isn't involved in oxygenation (gas exchange). Our alveoli are the only structures in our lungs that are actually exchanging gases, everything else is considered dead space (e.g. trachea, bronchus) because there is no exchange happening there. We also call those parts of the airway the conducting airway, since all they do is move air (conduction), whereas the respiratory airway refers to the alveoli since it is involved in gas exchange (respiration).
Since giraffes have very long necks and thus longer conducting airways, it would be reasonable to assume that they have much more dead space than humans do, proportionally speaking of course.