A graph of the relationship between the percentage oxygen saturation of blood and the partial pressure (or tension) of oxygen. The curve is S-shaped and indicates that haemoglobin has a high affinity for oxygen. The blood becomes highly saturated at relatively low oxygen partial pressures but, within respiring tissues, a small drop in oxygen partial pressure results in a big fall in oxygen saturation of the blood. During exercise, increased temperature and hydrogen ion concentration affect the oxygen-haemoglobin dissociation curve in such a way that more oxygen can be unloaded to supply the active muscles (see Bohr shift).
oxygen-haemoglobin dissociation curve
Subjects: Sports and Exercise Medicine.