Carbon monoxide exerts its toxic primarily by:
- A- Reacting with blood enzymes to produce acidic substances.
- B- Decreasing the oxygen- carrying capacity of the blood.
- C- Reacting with amino acids in the body to form ammonia.
- D- Inhibiting the gag reflex.
- E- Paralyzing the muscles of the diaphragm.
The correct answer is B- Decreasing the oxygen-carrying capacity of the blood.
Here's why:
A- Reacting with blood enzymes to produce acidic substances:
Carbon monoxide does not directly react with enzymes in the body to create acidic substances. While some reactions with carbon monoxide can indirectly affect blood pH, this is not the primary mechanism of toxicity.
C- Reacting with amino acids in the body to form ammonia:
This is not a primary mechanism of carbon monoxide toxicity. Carbon monoxide primarily affects hemoglobin, not amino acids.
D- Inhibiting the gag reflex:
While some studies suggest carbon monoxide might affect the nervous system, inhibiting the gag reflex is not the main cause of toxicity.
E- Paralyzing the muscles of the diaphragm:
Carbon monoxide does not directly paralyze the diaphragm muscles, although it can indirectly affect breathing by interfering with oxygen delivery.
B- Decreasing the oxygen-carrying capacity of the blood:
This is the correct answer. Carbon monoxide has a high affinity for hemoglobin, the protein in red blood cells that carries oxygen. When carbon monoxide binds to hemoglobin, it prevents oxygen from binding, essentially starving the body of oxygen. This can lead to a variety of symptoms, including headaches, dizziness, nausea, vomiting, confusion, and eventually unconsciousness and death.
Therefore, the primary mechanism of carbon monoxide toxicity is its ability to decrease the oxygen-carrying capacity of the blood by competing with oxygen for binding sites on hemoglobin.
