What physiological effects does nitrogen have on the body at depth?

At depth, nitrogen has significant physiological effects on the human body, primarily due to increased pressure. As divers descend, the partial pressure of nitrogen in the lungs rises, leading to higher amounts of nitrogen being dissolved in the bloodstream and body tissues. This increased nitrogen absorption can have serious implications.

One of the primary concerns is nitrogen narcosis, often described as a state similar to intoxication, which can impair cognitive functions and judgment while diving. This effect usually occurs at depths greater than 30 meters (100 feet) and can lead to dangerous behavior if divers are not aware of their compromised mental state.

Additionally, ascending too rapidly after being exposed to high pressures can lead to decompression sickness, commonly known as "the bends." This happens when nitrogen, which has been absorbed into tissues under pressure, forms bubbles in the bloodstream as a diver ascends and the pressure decreases too quickly. This condition can cause severe pain and necessitates immediate medical attention.

In contrast, the other options do not accurately reflect the physiological effects that nitrogen has on the body at depth. Nitrogen does not improve oxygen absorption and has notable negative effects rather than having no effect at all. Claims that nitrogen enhances performance in deep diving are also misleading because the risks associated with nitrogen narcos