Scuba Diving
and pressure changes in the blood
Le Chateliers Principle
How do we do it?
The pressure that the water exerts on a divers body continues to increase as the diver descends, causing many changes in the body. Most of these changes are a result of the body attempting to stay at equilibrium. Firstly, as stated in Boyles Law (P1V1=P2V2) when pressure increases, the volume of gas will decrease. This stays true in the human body. As the pressure increases, the gases within the divers body will compress and take up a smaller volume. As the diver ascends, they must do so slowly to allow the body time to readjust. If a diver rises too quickly, vessels in the lungs may burst as a result of the volume increasing too rapidly. When the pressure is increased, our bodies also have difficulty using access nitrogen, which we inhale along with oxygen on a daily basis. The body absorbs small amounts of nitrogen along with oxygen, but the nitrogen cannot be dissolved at normal pressure. Higher pressures allow the nitrogen to be absorbed into the blood along with the oxygen. The reaction is as follows...
O2 (g) + N2 (g) ⇋ 2NO (g)
When the pressure decreases, the nitrogen monoxide decomposes to form oxygen and nitrogen gas, if the pressure decreases too quickly the nitrogen gas will not have time to be completely removed from the tissue s and may form gas bubbles. This can cause an illness that is commonly known as decompression sickness or "the bends".