See Figure 17-3 . Gas Laws Introduction - There are some gas laws that must be understood in order to understand the physiology of respiration. The atmosphere is a mixture of gases. Dalton's law states that the total pressure of the mixtuure of gases is the sum of the pressures of the individual gases. The pressure of an individual gas in a mixture of gases is known as the partial pressure of the gas.
Gases move from areas of higher pressure to areas of lower pressure .
As the volume of a gas increases, the pressure of the gas decreases, and vice versa. In other words, the relationship between the pressure and volume of a gas is an inverse relationship. The pressure of a gas at the interface between the gas and the liquid affects how much of the gas dissolves in the liquid. The higher the pressure of the gas, the more of the gas will dissolve. A higher gas pressure causes the more gas molecules to come in contact with the liquid resulting in more gas molecules moving from the gas phase and entering the liquid.