Lecture 24- Pulmonary gas exchange Flashcards Preview

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Flashcards in Lecture 24- Pulmonary gas exchange Deck (24):
1

what element is has the highest composition in both atmospheric pressure and at alveoli saturated with 6.18% water vapor

Nitrogen

2

total pressure exerted by the mixture of non-reactive gases is equal to the sum of the partial pressures of individual gases

dalton's law

3

for a fixed amount of an ideal gas kept at a fixed temperature, pressure and volume are inversely proportional

boyle's law

4

at a constant temperature, the amount of a given gas that dissolves in a given type and volume of liquid is directly proportional to the partial pressure of that gas in equilibrium with that liquid

henry's law

5

what is the ideal gas law

P= nRT/V

6

what is the partial pressure of O2 at alveolar membrane

150 mm Hg

7

what is the partial pressure of CO2 at alveolar membrane

0.12 mm Hg

8

what is the solubility of oxygen and carbon dioxide and what does this mean

oxygen= 0.024
CO2= 0.57
CO2 is more soluble in water than oxygen and therefore will exert a partial pressure for a given concentration that is less than 1/20th that of oxygen

9

define vapor pressure of water

partial pressure exerted to escape form liquid phase to the gas phase

10

what is the value for vapor pressure at normal body temperature

47 mm Hg

11

what factors affect rate of gas diffusion in a fluid

solubility of gas in fluid
cross-sectional area of the fluid
distance through which the gas must diffuse
molecular weight of gas
temperature of fluid

12

what is the value for the functional residual capacity of the lungs in the average man

2300 ml

13

what is oxygen concentration in the alveoli and its partial pressure controlled by

rate of absorption of oxygen in the blood
rate of new oxygen entry into the lungs (alveolar ventilation)

14

what is carbon dioxide concentration in the alveoli and its partial pressure controlled by

rate of CO2 excretion
alveolar ventilation

15

what happens to alveolar PCO2 as alveolar ventilation increase

it decreases

16

what happens to alveolar PCO2 as rate of excretion increases

it increases

17

what factors determine how rapidly gas will pass through the respiratory membrane

membrane thickness
membrane surface area
diffusion coefficient of gas in the substance of the membrane
partial pressure difference of gas between the 2 sides of the membrane

18

define ventilation-perfusion ratio

alveolar ventilation/blood flow

19

what is the normal Va/Q

0.8

20

where is gas exchange completed during normal ventilation

initial 1/3 of capillary

21

what happens to blood gas composition when there is an airway obstruction

it remains unchanged

22

what happens to alveolar gas composition when there is a vascular obstruction and why

it does not change because there is no blood contact (creating a physiologic shunt)

23

what is the normal alveolar perfusion for PO2 and PCO2

PO2= 104mm Hg
PCO2= 40 mm Hg

24

what are the alveoli partial pressure of O2 and CO2 when Va/Q is infinity

O2= 149mm Hg
CO2= 0 mm Hg