Lecture 29 Flashcards
What process drives gas exchange in the lungs?
diffusion; from high to low pressure (= concentration gradient)
What is partial pressure? If our atmosphere is ~20% oxygen, what is the partial pressure of oxygen?
the individual contributions to the overall gas pressure by the different gases in a mixture; if O2 is ~20% of our atmosphere then the partial pressure of O2 (= concentration) is 20% of atmospheric pressure (760mmHg).
What process transports gases in the circulation between the lungs and tissues?
bulk transport due to blood being circulated.
Why must we remove CO2 from our body?
To avoid acidosis
When the temperature is constant, volume changes, pressure will cause _____ ____ of air either in or out of our lungs as described by Boyles law equation.
bulk flow
A fixed mass of dry gas exerts increasing pressure with decreasing volume and increasing temperature (and visa versa), behaviors which can be summarized by what equation?
Gas Law: P1V1/T1 = P2V2/T2
What is Boyle’s Law equation if the temperature is constant?
Boyle’s Law equation: P1V1 = P2V2
Atmospheric pressure is due to the effect of _____ on the gases that form our atmosphere.
gravity
At sea level and standard temperature, the Earth’s atmosphere exerts a total pressure of ________.
760mmHg
What is the partial pressure of the gases of the atmosphere?
For N2 (Pn2) is therefore given by 78.6% of 760mmHg = 597mmHg For O2 (Po2) is therefore given by 20.8% of 760mmHg = 159mmHg For CO2 (Pco2) is therefore given by 0.04% of 760mmHg = 0.3mmHg
What is 1% of the atmosphere made of that is not N, O2, or CO2?
1% Argon which is a “noble” gas and totally inert
T or F? At ~ 20,000 feet atmospheric pressure is less than half normal which means the Po2 is less than half and will not saturate hemoglobin resulting in anoxia.
True
At normal pressures, what are the physiological effect of Nitrogen and Argon?
Nitrogen and Argon have no known physiological effect. However, if you breathe in pressurized air, you can force nitrogen into solution. (The Bends)
What is vital for gas diffusion/exchange and viability in our lungs?
Moist lungs.
What is the pressure exerted water vapors in our lungs?
47 mmHG (Saturated Water Vapor Pressure: SWVP)
T or F? Between breaths our alveolar pressure must equal the surrounding atmospheric pressure, (= 760mmHg)
True
How do you calculate the Po2 of our lungs?
(760 mmHg - 47 mmHg) x 20.8% = 148 mmHg
What is solubility coefficient of CO2 and O2?
CO2 = 0.57 O2 = 0.024
CO2 has only _____ of the partial pressure of equivalent amount of O2 in solution.
a. 1/5th
b. 1/10th
c. 1/20th
c. 1/20th
How is partial pressure calculated with solubility coefficient?
partial pressure = concentration of dissolved gas/solubility coefficient
By what process does oxygen transfers to the alveoli of the pulmonary capillaries?
Diffusion