How does carbon monoxide (CO) poisoning work?

Carbon monoxide poisoning occurs primarily because carbon monoxide has a much greater affinity for hemoglobin than oxygen does. When carbon monoxide is inhaled, it binds to the hemoglobin in red blood cells, forming carboxyhemoglobin. This binding reduces the hemoglobin's ability to transport oxygen, leading to tissue hypoxia. In other words, while oxygen is necessary for cellular respiration and energy production, the presence of carbon monoxide inhibits the delivery of oxygen to vital organs and tissues, causing symptoms of poisoning.

The other choices do not accurately describe the effects of carbon monoxide. For example, carbon monoxide does not enhance oxygen delivery—rather, it dramatically decreases it. Additionally, carbon monoxide does not prevent carbon dioxide absorption; its primary action pertains to the uptake and transport of oxygen. Lastly, there is no evidence to support that carbon monoxide facilitates healing; instead, it can lead to significant physiological damage if exposure continues. Thus, the correct understanding of carbon monoxide's mechanism of action is crucial in recognizing and treating poisoning cases effectively.