The oxygen-carrying flask: a representational transform of the oxygen dissociation curve of hemoglobin

The teaching of oxygen transport by hemoglobin is supported by a graphic depiction of the sigmoid O2 dissociation curve of hemoglobin. However, a reconstruction of the same curve into an alternate paradigm, the "O2-carrying flask," affords a visual demonstration of the significance of its sigmoid shape and the implications of its shifts, which should be useful in elucidating certain aspects of O2 transport to undergraduate students of physiology. This article provides a mathematical justification for the flask design.