What is the consequence of carbon monoxide binding to hemoglobin more strongly than oxygen?

• A. Increased oxygen delivery
• B. No effect on oxygen transport
• C. Elevated carbon dioxide levels
• D. Reduced oxygen transport leading to hypoxia

Answer: (D)

Carbon monoxide’s strong grip on hemoglobin blocks oxygen from binding and forming carboxyhemoglobin, drastically reducing the blood’s oxygen-carrying capacity. Add to that the leftward shift of the oxygen-hemoglobin dissociation curve, which means the oxygen that is bound is held more tightly and less readily released to tissues. The result is less oxygen delivered to cells, causing tissue hypoxia. This is why the consequence is reduced oxygen transport leading to hypoxia. It wouldn’t increase oxygen delivery, and while CO exposure affects overall gas exchange, it doesn’t directly raise carbon dioxide levels—the primary issue is insufficient oxygen reaching tissues.