# Gas Exchange and Transport Quiz 1.txt

 The flashcards below were created by user coreygloudeman on FreezingBlue Flashcards. What is the difference between the normal gradients in oxygen and carbon dioxide partial pressures between the atmospher and tissues? Simple diffusion. For oxygen, it is a decreasing amount of tension from atmospheric to the cells. For CO2 it is opposite, from greatest amount at the cell to the least amount in the atmosphere. This aids the lungs in gettings rid of CO2 Why are partial pressure gradients for oxygen and carbon dioxide important within the body? Because they are what allow for gas flow in and out of the lungs How do you determine alveolar oxygen and carbon dioxide partial pressures? PACO2 = VCO2 x 0.863 / VANormal value is 200 ml/min and VA is alveolar ventilation which is normally 4.3 L, so...PACO2 = 200 mL/min x 0.863 / 4.3 L/min = (approx) 40 mmHg How is PACO2 maintained? by increasing or decreasing the rate of breathing How do you apply the air equation in determining PAO2? PAO2 = FiO2 x (PB - PH20) - PACO2/RIF the FIO2 is 60% or greater the correction for R can be droppedFiO2 = fractional concentration of inspired oxygenPB = barometric pressurePH20 = water vapor tension (47 mmHg at 37 C)PACO2 = alveolar partial pressure of carbon dioxideR = respiratory exchange ratio (nomarl value is 0.8) which is the ratio of carbon dioxide excretion to oxygen uptake.Example: PAO2 = 0.21 (760 - 47) - 40 / 0.8 = 100 mmHg How do you compute the alveolar-arterial PO2 difference and the a/A ratio? Egan's pg. 239Normal difference is small, only 5 to 10 torr while breathing air and no more than 65 torr when breathing 100% O2P(A-a)O2 = PAO2 - PaO2Example: P(A-a)O2 = 449 - 50P(A-a)O2 ~ 400 torrAbnormal; 400 torr is very high. a/A = PaO2/PAO2Example: a/A = 50/449a/A = 0.11Only about 11%Abnormal; should be atleast 90% What is the relationship of oxygen and carbon dioxide in the lungs? As Oxygen goes up, Carbon dioxide goes down, and vice versa. How do you calculate alveolar nitrogen partial pressure? PAN2 = PB - (PAO2 + PACO2 + PH20)Example:PAN2 = 760mmHg - (100 mmHg + 40mmHg + 47mmHg)PAN2 - 760 mmHg - 187 mmHgPAN2 = 573 mmHg Authorcoreygloudeman ID128986 Card SetGas Exchange and Transport Quiz 1.txt DescriptionCrafton Hills College RESP 135 Gas Exchange and Transport Quiz 1 Updated2012-01-19T17:48:35Z Show Answers