Lung Volumes to CO Poisoning

Question 1

Define tidal volume

Answer 1

the volume of one “normal” breath

Question 2

Define minute volume

Answer 2

total air inhaled and exhaled in one minute

-tidal volume x respiration rate

Question 3

Approximately how much of a persons tidal volume is actually involved in respiration

Answer 3

~70%

Question 4

What is the anatomical dead space

Answer 4

the ~30% of a tidal volume that is not involved in respiration

Question 5

Define alveolar ventilation rate

Answer 5

The volume that actually reaches the respiratory zone in one minute
-70% x minute volume (tidal volume x respiration rate )

Question 6

Define inspiratory reserve volume

Answer 6

the air volume you can take in, over the tidal volume by a forceful inhalation

Question 7

Define expiratory reserve volume

Answer 7

the amount of air volume you can exhale over your tidal volume

Question 8

Define residual volume

Answer 8

the air that cannot be exhaled from the alveoli or the non collapsible airways

Question 9

Can residual volume be determined by spirometry

Answer 9

No

Question 10

Define inspiratory capacity

Answer 10

tidal volume + inspiratory reserve volume

Question 11

Define expiratory capacity

Answer 11

tidal volume + expiratory reserve volume

Question 12

Define vital capacity

Answer 12

inspiratory reserve volume+ tidal volume + expiratory reserve volume

Question 13

Define total lung capacity

Answer 13

Vital capacity + residual volume

Question 14

What 3 factors is alveolar air dependent on

Answer 14

1. composition of inspired air
2. alveolar ventilation
3. concentration of dissolved gases in mixed venous blood

Question 15

What 2 gas laws are important for respiration and what do they state

Answer 15

Dalton’s law= the total pressure of mixed gas is calculated by adding all the partial pressures of the gases that compose the mixed gas

Henry’s law= the quantity of gas that will dissolve in a liquid is proportional to the partial pressures of the gas and its SOLUBILITY

Question 16

Why is Dalton’s law important for respiration

Answer 16

partial pressures determine the movement of O2 and CO2 from the:

• atmosphere and the lungs
• lungs and the blood
• blood and the tissue

gas flows from high partial pressure to lower partial pressure

Question 17

Why is Henrys law important for respiration

Answer 17

In body fluids the ability for a gas to stay in solution is greater when its partial pressure is greater and when its solubility is higher

so we can drive O2 into the tissue by increasing pO2

Question 18

What is the clinical application of Henrys law

Answer 18

hyperbaric chambers

Question 19

What gas has higher solubility O2 or CO2

Answer 19

CO2 , 24 times as much

Question 20

In external respiration is the diffusion of O2 from the alveoli to the blood and diffusion of Co2 from blood to the alveoli dependent on each other

Answer 20

No these 2 flows are independent of each other

Question 21

How does surface area affect gas exchange

Answer 21

the more surface area the faster and easier gas exchange is

Question 22

How does diffusion distance affect gas exchange

Answer 22

With greater diffusion distance, you get less gas exchange

Question 23

How does the the build up of interstitial fluid effect diffusion distance

Answer 23

more fluid =greater diffusion distance= less gas exchange

Question 24

Define PaO2

Answer 24

the partial pressure of dissolved unbound O2 in arterial blood

Question 25

Define SaO2

Answer 25

measurement of O2 that is bound to Hgb in arterial blood (so before tissue)

Question 26

Define SpO2

Answer 26

measurement of O2 that is bound to Hgb peripherally, it is what is measured by pulse oximeter

Question 27

What O2 measurement are from arterial blood draws

Answer 27

PaO2 and SaO2

Question 28

How does a pulse oximeter measure SpO2

Answer 28

colorimetric measurement

Question 29

Does CO or O2 have a higher affinity for Hgb

Answer 29

CO

Question 30

In CO poisoning what type of measurements will you see in PaO2, SaO2, and SpO2 and why

Answer 30

PaO2 = increases, because CO knocks of O2 from Hgb so more O2 is dissolved in plasma

SaO2= reduced, because CO is bound to Hgb not O2

SpO2= stays the same, because carboxyHgb and oxyHgb are both red