PADI Divemaster Certification Practice Exam

What factor influences the amount of nitrogen that dissolves into tissues?

1. Water temperature

2. Salinity of the water

3. Depth and time

4. Amount of exercise

The correct answer is: Depth and time

The amount of nitrogen that dissolves into tissues is primarily influenced by depth and time. As a diver descends deeper into the water, the increased pressure causes more nitrogen to dissolve in the body tissues according to Henry's Law, which states that the amount of gas that dissolves in a liquid is directly proportional to the pressure of that gas above the liquid. This means that at greater depths, the partial pressure of nitrogen increases, allowing more nitrogen to be absorbed by the body. Additionally, the duration of the dive also plays a crucial role. The longer a diver remains at a certain depth, the more nitrogen accumulates in the tissues. This accumulation can lead to increased risks of decompression sickness (the bends) when ascending, as the nitrogen must be safely off-gassed. While factors like water temperature, salinity, and physical exertion can have effects on diving physiology, they do not directly impact the amount of nitrogen that is dissolved in the tissues to the same extent as depth and time. Water temperature can influence gas solubility, but the direct relationship to pressure and time at depth is more significant. Salinity can affect buoyancy and dive conditions, but again, it is not a primary factor in nitrogen absorption. Similarly, while exercise can