What physiological factor contributes to nitrogen narcosis?

The physiological factor that contributes to nitrogen narcosis is the elevated partial pressure of nitrogen (N2) experienced at increased depths during diving. As a diver descends, the surrounding pressure rises, leading to a greater density of gases, including nitrogen, in the lungs. This increased pressure causes the partial pressure of nitrogen in the body to rise significantly.

Under normal atmospheric conditions, nitrogen is inert and does not affect the body; however, when its partial pressure increases, as it does during deep diving, nitrogen can diffuse into the lipid membranes of the nervous system and brain. This effects neurological function and has a narcotic effect similar to alcohol, which can lead to impaired judgment, decreased motor coordination, and altered perception. These symptoms are what divers experience as nitrogen narcosis, often described as feeling euphoric or disoriented.

Understanding this mechanism is essential for divers, as it highlights the importance of managing depth and exposure time to prevent narcosis and ensure safe diving practices.