Unit 2, L4 Ventilation

Question 1

Equation for Ventilation

Answer 1

V = Frequency * volume so 15/min * 500 mL = 7.5 L/min

Question 2

Boyle’s Law

Answer 2

Pressure-volume law. The volume of a given gas varies inversely with the applied pressure when temperature and mass are constant

Question 3

Charles’ Law

Answer 3

Temperature volume law. The volume of a given amount of gas held at constant pressure is directly proportional to the Kelvin temperature

Question 4

Gay-Lussac’s Law

Answer 4

Pressure-temperature law. The pressure of a given amount of gas at constant volume is directly proportional to the Kelvin temperature

Question 5

Combined gas law

Answer 5

The ratio between the pressure-volume product and the temperature remains constant.

(P1V1)/T1 = (P2V2)/T2

Question 6

Avogadro’s law

Answer 6

Volume-amount law. If the amount of gas in a container is increased, the volume increases

Question 7

The ideal gas law

Answer 7

The state of an amount of gas is determined by its pressure, volume, and temperature
PV=nRT

Question 8

Dalton’s Law of Partial Pressures

Answer 8

The total pressure of a mixture of non-reacting gases is the sum of their individual partial pressures

Question 9

Amagat’s law of partial volumes

Answer 9

The volume of a gas mixture is equal to the sum of the component volumes of each individual component

Question 10

Henry’s law of Gas Solubility

Answer 10

The concentration of a solute gas in a solution is directly proportional to the partial pressure of that gas above the solution

Question 11

Henry’s Law of gas solubility and gas in solution example

Answer 11

Concentration is equal to partial pressure of gas above solution and stays constant. Exact relationship, so if he tells us there is 100 mmHg of pO2 above the solution, we know there is exactly 0.13 mM of oxygen dissolved in the solution

Question 12

PAO2 definition and value

Answer 12

Alveolar partial pressure of oxygen, 100 mmHg

Question 13

PaO2 definition and value

Answer 13

Arterial partial pressure of oxygen, 95 mmHg

Question 14

PvO2 definition and value

Answer 14

Venous partial pressure of oxygen, 40 mmHg

Question 15

Composition of ambient air

Answer 15

Mostly nitrogen, oxygen

Question 16

Gas fractions

Answer 16

Sum of individual gas fractions = 1

1 = FN2 + FO2 + etc

Question 17

Partial pressures (Dalton)

Answer 17

Sum of partial pressures = Total pressure

Question 18

Barometric pressure is what value

Answer 18

760 mmHg at sea level

Question 19

At sea level, what is the pressure equation?

Answer 19

P atm = 760 mmHg = PN2 + PO2 + etc

Question 20

Partial pressure of N2 in atmospheric air

Answer 20

Its 79% N2, so 760 mmHg * 0.79 = 600 mmHg

Question 21

Partial pressure of O2 in atmospheric air

Answer 21

21% O2, so 760 * 0.21 = 160 mmHg

Question 22

Our atmospheric water vapor pressure is

Answer 22

160 mmHg O2

Question 23

Equation for water vapor pressure

Answer 23

PIo2 = (Patm - P water) * FO2

150 mmHg = (760 mmHg - 47 mmHg) * 0.21

Question 24

Water vapor pressure is always what value

Answer 24

47 mmHg

Question 25

Ideal alveolar oxygen equation

Answer 25

The partial pressure of oxygen in the alveoli is the partial pressure of oxygen that enters the alveoli minus the partial pressure of oxygen that leaves the alveoli. ``` PAO2 = PO2 entering - PO2 leaving PaO2 = PiO2 - PACO2/R ``` The partial pressure of oxygen leaving the alveoli is the partial pressure of alveolar CO2 (PACO2) divided by the respiratory quotient (R)

Question 26

Respiratory Quotient R is what, and what is the standard R

Answer 26

The ratio of CO2 eliminated to O2 consumed. Standard R for mixed diet is about 0.8

Question 27

Ideal alveolar oxygen equation

Answer 27

PAO2 = PiO2 - PACO2/R | 100 mmHg = 150 mmHg - (40 mmHg/0.8)

Question 28

If you breathe 100% oxygen, what is the PAO2 (PACO2 is 45 mmHg, R is 0.8)

Answer 28

``` PAO2 = ((Patm-Pwater)*FO2)-PACO2/R X = ((760-47)*1.0)-45/0.8 X = 713-56 X = 657 mmHg ```

Question 29

The amount of CO2 in the alveoli is _________ to the amount of CO2 produced by the tissue, and _________ to the ventilation rate

Answer 29

The amount of CO2 in the alveoli is directly proportional to the amount of CO2 produced by the tissue, and indirectly proportional to the ventilation rate

Question 30

Alveolar ventilation equation

Answer 30

Va = VCO2/PCO2 * K ``` Va = Alveolar ventilation rate VCO2 = Rate of carbon dioxide exhalation PCO2 = Partial pressure of arterial carbon dioxide ```

Question 31

Doubling ventilation will __________ PCO2

Answer 31

Halve PCO2

Question 32

Halving ventilation rate will __________ PCO2

Answer 32

Double PCO2

Question 33

Alveolar CO2 is determined by _________ and ________

Answer 33

Metabolism and ventilation (rate of elimination)

Question 34

More ventilation occurs at ________ of the lungs than at the ______ of the lungs

Answer 34

More ventilation occurs at the base of the lungs than at the top of the lugns

Question 35

Pleural pressure at the ___________ of the lungs is ___________ than pleural pressure at the __________ of the lungs

Answer 35

Pleural pressure at the bottom of the lungs is a little bit greater than pleural pressure at the top of the lung

Question 36

Single Breath Nitrogen Test

Answer 36

Patient breaths in 100% O2 to TLC and didn't breathe in any N2, but there was already N2 in the lungs from previous breaths. Initial breath out is 100% O2, then some N2 starts to come out with the mixture. Most of the lung is when you see a mixture of O2 and N2. Alveoli are slow to empty or the airways that are closed off to the O2 breathe will be at the very end, this is basically only N2. This is telling you that the O2 you inhaled didn't make it into those spaces

Question 37

Ventilation equations

Answer 37

Vt = VD + VA VA = Vt - Vd

Question 38

How to measure anatomic dead space

Answer 38

Fowler's method, a single breath of oxygen. Breathe in 100% O2, mix with N2 that is already in the lungs, and some will stay at 100% in the conducting zone, and can measure the amount of N2 that is let out

Question 39

Physiological dead space definition

Answer 39

Total volume of gas that does not participate in gas exchange. Anatomic dead space + alveolar dead space (ventilated but not perfused)

Question 40

Measuring physiological dead space

Answer 40

Borh's method, expired CO2. Measuring Co2 that comes out of the expired air, so breathing in CO2-free air, mix with lungs, and CO2 free air will stay in anatomic dead space. CO2 from alveolar space will be mixed in and we can measure that when it comes out

Question 41

Equation for measuring physiological dead space using Borh's method

Answer 41

``` VD = Vt * (PACO2-PECO2)/PACO2 VD = 500 * (40-28)/40 VD = 150 mL ```