Final answer:
When arterial blood collected in a heparinized syringe is exposed to room air, it causes a decrease in pH, an increase in PCO₂, and an increase in HCO₃¯. These changes in pH and PCO₂ affect the oxygen-hemoglobin dissociation curve, reducing the affinity of hemoglobin for oxygen.
Step-by-step explanation:
When arterial blood collected in a heparinized syringe is exposed to room air, it causes a decrease in pH, an increase in PCO₂ (partial pressure of carbon dioxide), and an increase in HCO₃¯ (bicarbonate ion).
This is because when CO₂ in the blood reacts with water, it forms bicarbonate ions and hydrogen ions, resulting in a decrease in pH. The increase in CO₂ also increases the partial pressure of carbon dioxide in the blood. These changes in pH and PCO₂ affect the oxygen-hemoglobin dissociation curve, reducing the affinity of hemoglobin for oxygen.