The oxyhemoglobin dissociation curve depicts the connection between arterial oxygen tension (PaO2 or partial pressure of oxygen in the arteries) and the quantity of oxygen bound to hemoglobin—the hemoglobin saturation. The quantity of oxygen loaded onto hemoglobin grows curvilinearly as arterial oxygen tension rises, resulting in a sigmoid-shaped graph—the outcome of increased oxygen-binding after the initial binding of oxygen.