Physiology of the Hematopoeitic and Lymphoreticular Systems
The affinity of hemoglobin for oxygen is increased by which of the following?
ExplanationHemoglobin’s affinity for oxygen is increased by carbon monoxide. In carbon monoxide poisoning, carbon monoxide not only displaces O2 from hemoglobin, it also makes it more difficult for the O2 that is bound to Hb to dissociate from it in the tissues. Increasing H+ ion concentration (decreasing pH) by metabolic acidosis or respiratory acidosis (decreased alveolar ventilation) decreases the affinity of hemoglobin for O2. Exercise decreases the affinity of Hb for O2 by increasing the temperature of the exercising muscles. A decrease in arterial PO2 (hypoxemia) decreases Hb’s affinity for oxygen.
