When one thinks about whether
circulation will or will not be effected by diving, many would
think that human physiology would be the only field to research
under. This idea could easily be understood because this topic
concerns circulation and the heart. However, the physics of diving
and water pressure play just as large of a role in this idea.
The main ideas from physics would have to be the laws created
by Boyle, Charles, Dalton and Henry.
Both Boyle's law and Charles's law have to do with how different conditions one faces while diving affects different gasses. Again it may seem odd to many that gasses would be in consideration when talking about the circulatory system because everyone knows that blood is a liquid, right? Well, this is true but people must also consider the oxygen (and other gasses) that the blood is carrying. These two laws directly affect these gasses in the blood. Boyle's law, saying that as a person dives deeper more pressure is put on the gasses and they become forced to compress. This would mean that the oxygen and other gasses compress and become denser in the blood stream. In addition, Charles's law also concerns the oxygen and other gases in the blood stream. Charles's law states that as the temperature decreases the gases compress and become denser. So, when a person dives both the temperature and the pressure make the gases in the blood compress and become denser.
While Boyle's law and Charles's law both talk about gases compressing during a dive, Henry's and Dalton's laws refer to gases dissolving into liquids and how gases make up different percentages of pressure. Once the gases have compressed there is a point where they would not have a place to go. Henry's law says that if the pressure is enough a gas will dissolve into a liquid that is present. This does happen in divers that experience "the bends". In a somewhat similar situation, nitrogen narcosis occurs. At deep depths the pressure of different gases is taken out of the blood. This is where nitrogen narcosis occurs. If too much of the gas is dissolved into the blood a diver may experience a sense of euphoria and behave as a drunk might. The problem with this is that a diver may be delirious and take their mouthpiece out or do something else that could jeopardize their life. The bends however is a little different. If the diver comes up too fast then the gases try to escape the blood and become a separate gas once again. However, if the diver is going to fast the gases will bubble and cause problems from pain in the joints to a heart attack. While these two conditions do not at all happen to all divers they are possibilities. That is not to say that divers who do not come up fast do not have gas dissolve back into their blood. Considering atmospheric pressure, gas is already dissolved into everyone's blood. However, with diving, more gas is dissolved in the blood. This, needless to say, has the possibility to affect circulation.
All in all there are many ways in which diving could affect circulation, many of which no one knows. But, it is known that Boyle's, Charles's, Dalton's and Henry's laws all the possibility to do so.