Physiology Spring L2 Ventilation

Front 1

What is the tidal volume? what is its abbreviation?

Back 1

this is the volume that fills the alveoli and the volume that fills the airways (anatomic dead space)

abb: V(t)

Front 2

What is the Inspiratory reserve volume? IRV

Back 2

this is the additional volume inspired above V(t)

Front 3

What is Expiratory reserve volume? ERV

Back 3

this is the additional volume expired below V(t)

Front 4

what is residual volume? RV

Back 4

this is the volume of gas left in the lungs after maximal forced expiration

Front 5

What two factors make up inspiratory capacity? IC

Back 5

this would be V(t)+ IRV

so tidal volume plus inspiratory reserve volume

Front 6

What two factors make up Functional residual capacity?

Back 6

this is ERV + RV

so expiratory reserve plus residual volume. so essentially all air after tidal volume exhale

Front 7

What is the vital capacity?

Back 7

this is IC+ ERV. so inspiratory capacity and expiratory reserve volume

this includes the tidal volume, inspiratory reserve volume, expiratory reserve volume.

Front 8

what things increase vital capacity?

Back 8

being a man, being big, fitness training

Front 9

what things decrease vital capacity?

Back 9

old age, loss of compliance due to disease

Front 10

what is included in the total lung capacity?

Back 10

this includes Vital capacity, and the residual volume. so tidal volumes, inspiratory and expiratory reserve, and residual volume

Front 11

what is the functional residual capacity?

Back 11

this is ERV + RV. expiratory reserve volume and residual volume.

this CANNOT be measured by spirometery

Front 12

What is another name for functional residual capacity?

Back 12

resting volume of the lungs

Front 13

What is the normal RV/TLC ratio?

Back 13

less than or equal to .25

Front 14

How does RV/TLC change during obstructive lung disease?

Back 14

it will increase in obstructive lung disease, due to an increase in Residual volume. aka cant blow out enough air.

Front 15

How does RV/TLC change during restrictive lung disease?

Back 15

this will increase, due to a decrease in total lung capacity. if the lungs cannot inflate as well, TLC will be lower

Front 16

What branches of the respiratory system are included in anatomic dead space?

Back 16

branches 0-16, the conducting airways

directly related to weight.

Front 17

Do alveoli in functional dead space participate in gas exchange?

Back 17

no they do not

Front 18

When would you expect to see functional dead space in alveoli?

Back 18

during V/Q mistmatch

Front 19

What are the 3 assumptions used when thinking of physiologic dead space?

Back 19

all CO2 in expired air comes from gas exchange only

there is no CO2 in inspired air

physiologic dead space neither exchanges nor contributes CO2

Front 20

If there is physiologic dead space, how will expired CO2 relate to alveolar CO2 pressures?

Back 20

If there is dead space, the pressure of expiratory CO2 will be LOWER than expected, and lower than the blood CO2 levels.

this is due to the lack of CO2 in the dead space, so it dillutes out the CO2 from functioning alveoli slightly.

Front 21

What is the relationship between alveolar and arterial CO2 levels?

Back 21

they should be directly matched due to diffusion in the lungs

Front 22

what is the equation for calculating physiological dead space?

Back 22

Vd= Vt X PAco2-PEco2/ PAco2

This uses the fraction given, to see if the expired air is being diluted at all. if Expired CO2= arterial CO2= then the fraction is zero, and dead space is zero.

Front 23

What is minute ventilation? how is it calculated?

Back 23

this the total rate of air movement in and out of the lungs.

MV= Vt x Breaths/Min

minute ventilation= tidal volume X breaths per min.

Front 24

what does alveolar ventilation take into account?

Back 24

this corrects for physiologic dead space

Front 25

what is the equation for alveolar ventilation?

Back 25

this is the rate of ventilation of the alveoli.

Va= (Vt- Vd) X breaths per min

alveolar ventilation= (tidal volume- physiological dead space) X breaths/min

Front 26

What does the alveolar ventilation equation solve for?

Back 26

this looks at the rate of Co2 excreted into expired air, in ml/min

Front 27

using the alveolar ventilation equation, at constant CO2 production, what determines PAco2?

Back 27

this is determined by alveolar ventilaiton rate.

a faster vent rate, will decrease the concentration of CO2 in expired air, and thus artery CO2

Front 28

what does the relationship between PAco2 and Va (rate)

at constant CO2 production?

Back 28

this is hyperbolic, the faster the alveolar vent rate, the lower the PAco2 and thus Paco2

Front 29

How does the alveolar vent curve shift during increased CO2 production?

Back 29

this shifts the curve to the right, requiring the vent rate to change to maintain constant partial pressure of CO2.

Front 30

What is the forced vital capacity?

Back 30

this is the total volume of air that can be expired after maximal inspiration

Front 31

What is FEV1?

Back 31

this is the forced expiratory volume after 1 second

Front 32

what is the FEV1/FVC ratio supposed to be?

Back 32

.8

Front 33

how does FEV1/FVC change during fibrosis/restrictive disease?

Back 33

this lowers the FVC, so it increases the FEV1/FVC ratio

Front 34

how does FEV1/FVC ratio change during obstructive diseases?

Back 34

this will lower FEV1, but FVC will only slightly shrink.

this means that FEV1/FVC will be lower/smaller.