5.3 Pulmonary

Question 1

we are designed to have ____ gradients for exchange?

Answer 1

partial pressure

*O2 leaves capillaries into tissue where CO2 leaves tissue, at alveoli it is opposite; all due to PP

Question 2

Parital pressure gradients are the driving force of?

Answer 2

diffusion at both pulmonary capillaries AND body tissue

Question 3

average pressure at sea level

Answer 3

760mm of Hg

*O2, CO2, N2 and each other gas in the atmosphere contribute a part of the overall 760 mm Hg total barometric pressure

Question 4

so what IS partial pressure?

Answer 4

the pressure contibution of a gas to overall totoal pressure

*doesn’t matter which gas you are talking about! diffusion is by partial pressure

Question 5

1) what is another way of saying partial pressure?

2) of mm Hg?

Answer 5

1) tension

2) torr

Question 6

units for

1) cardio
2) ventilation mechanics
3) gas exchange

Answer 6

1) mm Hg
2) cm of H2O
3) mm Hg

Question 7

what is dalton’s law?

Answer 7

in a gas mixture, the pressure exerted by each individual gas in independent of the pressures of the other gases in the mixture

Question 8

how do you calculate partial pressure?

Answer 8

% of total gas mixture times total ressure

Question 9

define dry atmospheric air?

Answer 9

completly devoid of air

Question 10

what tow things happen to air when you breath it through nose?

Answer 10

1) warmed to 37 celcius

2) 100% humidified to exert 47 torr

Question 11

what are standard condition of air we breath?

Answer 11

37 degrees C
100% humidified to exert 47 torr
O2 =21% of atmosphere

Question 12

inspired air at 100% humidified at 37 degrees exerts ____ torr

Answer 12

47

Question 13

is humidified 47 torr part of 760?

Answer 13

yes. You must substract 760- 47 = 713

Question 14

how do you calculate oartial pressure?

Answer 14

% of total gas mixture multiplies by total pressure

Question 15

PO2 vs OiO2 vs P,AO2?

Answer 15

• PiO2= PP of INspired oxygen

- P,A = PP of alveolar oxygen

Question 16

what changes your calculations of PP?

Answer 16

atmospheric pressure! (aka total barometric pressure)

Question 17

what greatly affects barometric pressure?

Answer 17

altitude

Question 18

what are typical #s of inspired and alveolar gas?

Answer 18

Inspired

• PiO2= 150
• CO2= 0

alveolar

• PaO2= 100
• CO2= 40

Question 19

what determiens PaO2 and PaCO2?

Answer 19

1) alveolar ventilation

2) O2 uptake from and CO2 delivery to the lung

Question 20

why isn’t alveolar gas PPs for O2 150 like when it is inspired?

Answer 20

O2 is castantly diffusiong out of alveoli into pulmonary capillaries. So even at rest, you can’t fill up to 150 bc O2 is always leaving (can’t fill up bath with a drain open)
**same thing happens with CO2 but in other direction

Question 21

alveolar oxygen and CO2 are regulated by?

Answer 21

alveolar ventilation rates

Question 22

hypo vs hyperventilation relationship woth O2 and CO2 levels?

Answer 22

• hypo= increase CO2; decrease O2

* hyper= decrease CO2; increase O2

Question 23

normall ventilation of gas is about?

Answer 23

100

Question 24

why is O2 and CO2 relationship different?

Answer 24

bc we have a cap on how much oxygen we have. It is really determined by atmosphere

Question 25

at sea level, inspired O2 is at 150 meaning?

Answer 25

the highest you can drive O2 levels is 150

*so until that point, you have somewhat of a direct relationship bw alveolar ventilation and alveolar oxygen

Question 26

the amount of PP CO2 and O2 in alveoli in a typical healthy person regulates how much is in?

Answer 26

arterial blood

Question 27

driving force for simple diffusion?

Answer 27

either pressure or concentration gradients

Question 28

diffusivity of CO2 or O2 is greater?

Answer 28

CO2

Question 29

partial pressure of CO2 or O2 is greater?

Answer 29

O2

Question 30

how do this factors affect diffusion rate?

1) excericise
2) emphysema
3) pulmonary edema
4) alveolar fibrosis
5) supplemental oxygen

Answer 30

1) increase surface area
2) decrease SA and causes impairment
3) increase thickness and causes impairment
4) increase thickness and causes impairment
5) increases P1 - P2

Question 31

metabolically active cells have a lower PP intracellularly or extracellularly?

Answer 31

intracellularly

* lower PP = greater PP gradient of O2 = more O2 will diffuse into cell

Question 32

what happens with CO2 and O2 in metabolically active cells?

Answer 32

O2= influx
CO2= efflux (exit cells)