A&P 2- (2) respiratory gas laws

What is Boyles law?

P1V1=P2V2 -The pressure exerted by a gas or mixture of gases is created by collisions of moving gas molecules with the walls of the container, and with each other. - If the size of the container is reduced, the collisions become more frequent and the pressure increases. - The credit for expressing the relationship between gas pressure and volume was given to Robert Boyle in the 1600s. -his law states that if the volume of a gas is reduced, the pressure increases. If the volume increases, the pressure decreases.

Describe Dalton's law

His law states that the total pressure exerted by mixture of gases is the sum of the pressures exerted by the individual gases in the mixture -In dry air at an atmospheric pressure of 760 mm Hg, 78% of the 760 mm Hg is due to N2, 21% to O2, 0.04% to CO2, etc.

What is the ideal gas equation?

PV= nRT P= pressure; V= volume; n= moles of gas; T= temp; R= 8.3145 constant Can reduce it to —> *V= 1/P* which is the relationship saying that volume of gas increases, the pressure decreases, and vice versa

Why is O2's low solubility significant?

- The amount of O2-carrying molecules in the blood has a large influence on the O2-carrying capacity of the blood & therefore the availability of O2 to the tissues. - O2 will be slower to cross the respiratory membrane than CO2, & this will be exacerbated in pulmonary edema. • In some cases of pulmonary edema, arterial PO2 is low but arterial PCO2 will be normal. - "Slow" diffusion of O2 into the pulmonary capillaries means that there will not be time for PO2 to equilibrium b/w alveolar Air & blood PO2alv ≠ PO2cap

Movement of gas molecules from air into a liquid is directly proportional to 3 factors:

- The partial pressure gradient of the gas. - The solubility of the gas in the liquid. - Temperature.

If a container of water, that has not been in contact with air (PO2 = 0 mm Hg), is exposed to air with a PO2= 100mm Hg, Which direction will the oxygen move and until when?

-O2 will move into the water and dissolve -this process will continue until the P02 water = the PO2 air, that is diffusion will continue until amen equilibrium exists in which PO2 w = PO2 a and the mo mental of O2 from air —> water = movement of O2 from water —> air

When a gas is placed in contact with water, and there is a pressure gradient b/w the gas & the water, gas molecules will move according to the direction of the pressure gradient. • If gas pressure is higher in the water than in the gaseous phase, then gas molecules will ______ • If gas pressure is higher in the gaseous phase than in the water, then gas molecules will _____

A. leave the water. B. dissolve into the water.

Air flows whenever there is a _____ - Bulk flow of a gas is from an area of ____ to an area of ______

A. pressure gradient. B. higher pressure C. Lower pressure.

What is the difference between air and blood in terms of them both being fluids?

Air is a compressible fluid whereas you cannot compressed liquid. Air is it compressible mixture of gases

What does the ideal gas equation state?

It states that if the volume containing a gas increases, the pressure decreases, and if the volume of a gas decreases, the pressure increases

Oxygen has (high/low) solubility?

Low

What determines the PO2 of the O2 in the water? What about the concentration of a gas?

The concentration of 02 that is dissolved in the water (the partial pressure of the gas in solution) -However, the actual conc. of O2 in the air vs. the water at equilibrium will not be equal, even though the PO2 in air vs. the water are equal. -concentration of a gas at any given partial pressure is dependent on *solubility* Partial pressures are equal however, concentrations are not

^^ solubility = _____ Low solubility = _____

^^ movement of gas particles from air —> H2O @ low Partial pressure *(CO2)* low movement of gas particles from air —> H2O @ ^^ partial pressure *(O2)*

Henry's Law states that, at any given temperature, the amount of a gas in solution is proportional to the:

partial pressure of that gas.

The partial pressure exerted by a single gas is determined only by the ______of that gas in the mixture of gases. - Molecular size or mass has nothing to do with partial pressure.

relative abundance (% of the total)