Patient Case: A 28-year-old female marathon runner collapses during a race and is brought to the hospital. She is hyperventilating, and her arterial blood gas shows a partial pressure of oxygen (PaO2) of 110 mmHg (normal: 75-100 mmHg) and a PaCO2 of 25 mmHg (normal: 35-45 mmHg), suggesting respiratory alkalosis due to excessive CO2 removal. How does hemoglobin (Hb) facilitate the unloading of oxygen (O2) to the tissues in this patient during her run, considering the role of CO2?
