Which gas is known to shut down the nervous system?

The correct answer focuses on carbon monoxide (CO), which is known for its ability to interfere with the body's ability to transport oxygen in the bloodstream. When inhaled, carbon monoxide binds with hemoglobin in red blood cells far more effectively than oxygen does, forming carboxyhemoglobin. This significantly reduces the oxygen-carrying capacity of the blood, which can lead to suffocation at a cellular level, effectively shutting down the nervous system and other vital organs due to lack of oxygen.

While carbon dioxide (CO2) is a normal byproduct of metabolism, elevated levels can lead to respiratory acidosis and other issues, but it does not directly shut down the nervous system in the way carbon monoxide does. Oxygen is essential for maintaining cellular functions, including the activity of the nervous system. Nitrogen is an inert gas in terms of biological processes, and while it can cause issues at high pressures or concentrations, it does not directly affect the nervous system's operation in a manner similar to carbon monoxide.