30 Gas Transport and Ventilation Flashcards
Gas Law–The pressure of a gas =?
the sum of the partial pressure of all its constitutes
4 important gases in the body?
N2, O2, CO2, H2O
In the air, the atmospheric pressure is approximately equal to the sum of which two pressures?
N2 and O2
Atmosphere is approximately % N and % O?
79% N and 21% O
Atmospheric pressure at sea level mmHg?
760 mmHg
Is the PCO2 greater within the alveoli or in room air?
Much greater in alveoli
What is Henry’s Law?
Quantity of dissolved gas= partial pressure x solubility coefficient
What are the 3 forms carbon dioxide is transferred in the blood?
dissolved (5%), as bicarbonate (77%), and as carbamino compounds (18%)
What drives the diffusion of gases?
a pressure or concentration gradient
Does CO2 or O2 have a greater solubility?
CO2
Is the CO2 bound to hemoglobin bond strong?
No its weak.
What do red blood cells contain that facilitate combination of Co2 and water?
carbonic anhydrase
CO2 and water combine to form?
carbonic acid—dissociates to proton and bicarbonate
Does the bicarbonate stay in the RBC where it is formed?
no, it diffuses out because of concentration differences
What diffuses into RBC in order to maintain electroneutrality when bicarb diffuses out?
chloride—hence the chloride shift
What is the volume of gas inspired or expired with each breath?
Tidal Volume