Ventilation

Question 0

How much is tidal volume usually?

Answer 0

500 mL

Question 1

What is tidal volume?

Answer 1

Amount of air inspired and expired in normal breathing

Question 2

How much is the total lung volume?

Answer 2

Usually 4000 mL

Question 3

How much is the total lung capacity?

Answer 3

About 7000 mL

Question 4

What is vital capacity?

Answer 4

Amount that the lungs can expire after maximum inspiration

Question 5

How much is vital capacity?

Answer 5

Usually 6000 mL

Question 6

What is residual volume?

Answer 6

Amount of air remaining in the lungs after maximal respiration

Question 7

How much is residual volume usually?

Answer 7

1500 mL

Question 8

What is the functional residual capacity?

Answer 8

Volume left in lungs after normal expiration

Question 9

How much is the functional residual capacity, usually?

Answer 9

about 2500 mL

Question 10

What are two methods used to measure functional residual capacity?

Answer 10

Gas dilution technique and plethysmograph

Question 11

How does a plethysmograph work?

Answer 11

Measures change in pressure in a box of fixed volume

P1xV1=P2xV2
V1-V2=Change in volume

Question 12

What is total ventillation?

Answer 12

Amount of air entering and leaving lungs each minute

Question 13

How much is total ventilation usually?

Answer 13

500 mL x 15 rpm = 7500 mL/min

Question 14

How much air actually enters the alveoli from each 500 mL breath?

Answer 14

350 mL

Question 15

How can alveolar ventilation be calculated?

Answer 15

Amount of CO2 in exhalation divided by fractional constellation of CO2 in breath
Va = VCO2/PCO2 x K

Question 16

How can Nitrogen be used to measure dead space volume?

Answer 16

Pure O2 inhalation, measure how much N2 comes out

Question 17

How can CO2 be used to measure physiologic dead space?

Answer 17

Take fraction of CO2 in expired gas and compare it to alveolar gas.
Vd/VT = (PAco2 - PEco2) / PAco2

Question 18

Which areas of the lung are ventilated best?

Answer 18

Lower portions