Spirometry and gas laws

Question 1

FRC

Answer 1

functional residual capacity-volume in lung at end of quiet tidal breath. Determined by inward elastic recoil of lungs and outward elastic recoil of chest wall. 2.6-3.4L

Question 2

IC

Answer 2

Inspiratory capacity- TLC minus FRC. 2.3-3L

Question 3

TLC

Answer 3

Total lung capacity- Amt of air in lungs when maximally inflated. 4.9-6.4L

Question 4

RV

Answer 4

residual volume. Amt of air left in lungs after maximally deflated. 1.5-1.9L

Question 5

ERV

Answer 5

Expiratory Reserve Volume- FRC minus RV. 1.1-1.5L

Question 6

IRV

Answer 6

Inspiratory Reserve Volume- IC minus TV. 1.9-2.5L

Question 7

TV

Answer 7

tidal volume. .4-.5L

Question 8

VC

Answer 8

vital capacity- TLC minus RV. 3.4-4.5L

Question 9

What is FEV1? What is a normal value relative to FVC? How is it affected by obstructive and fibrotic diseases?

Answer 9

75%. obstructive=lower. restrictive=higher.

Question 10

what does a flow-volume loop look like? Why?

Answer 10

inspiratory curve is u-shaped and symetrical. Expiratory curve is asymmetric because flow is greatest at high volumes

Question 11

How do restrictive and obstructive disease affect lung volumes?

Answer 11

obstructive=increase lung volumes.

restrictive=decrease lung volumes

Question 12

what is the primary determinants of lung volumes

Answer 12

body size

Question 13

what volumes change with age?

Answer 13

RV increases. FRC increases. VC decreases. TLC doesn’t change.

Question 14

what is the most common way to measure lung volumes

Answer 14

helium dilution

Question 15

what is the volume of one mole of gas under std. condition

Answer 15

22.4

Question 16

at one atm. in dry air, what is the PO2? what is the dry fraction/

Answer 16

159mmHG. 0.2094

Question 17

What is the Total of all the partial pressures in a system? Of all the fractional concentrations?

Answer 17

PsubB, changes with altitude.

1.0

Question 18

what is the equation for Fg?

Answer 18

Fg=Pg/(PB-PH2O)

Question 19

what is PH2O at 37*? Does it change with temp? Changes in PB?

Answer 19

47mmHg. It changes with temp, not with PB because it is in equilibrium with the fluid conc of the lungs

Question 20

What is Henry’s Law?

Answer 20

Cg=K(Pg). Pg in liquid is same as gas above it but the conc of that gas depends on the solubility constant and is proportional to Pg

Question 21

What is STD atmospheric pressure? PAO2? PACO2? PvO2? PvCO2? V(dot)CO2? V(dot)O2?

Answer 21

760mmHg, 100, 40, 40, 45, 200ml/min, 250 ml/min