What causes nitrogen narcosis?

• A. Inert gases do not affect narcosis
• B. Oxygen partial pressure is the main cause
• C. Carbon dioxide narcosis is identical to nitrogen narcosis
• D. Inert gases vary on their potency, increased partial pressure of nitrogen

Answer: (D)

Nitrogen narcosis happens because, as a diver goes deeper, the ambient pressure increases and nitrogen becomes more soluble in body tissues, especially in the lipid membranes of nerve cells. This dissolved inert gas alters neuronal function, leading to narcotic effects such as euphoria, slowed thinking, and impaired coordination. The strength of this effect depends on the particular inert gas and how high its partial pressure becomes; inert gases vary in potency, and increasing the partial pressure of nitrogen specifically drives the narcosis.

Oxygen partial pressure can cause toxicity at high depths, but it is not the cause of narcosis. Carbon dioxide narcosis is a different issue related to CO2 buildup and acidosis, not the same mechanism as nitrogen narcosis.