ventilation and compliance

Question 1

anatomical dead space

Answer 1

~150ml

volume of gas occupied by conducting airways - so not available for gas exchange

Question 2

tidal volume

Answer 2

volume of air breathed in or out lungs at each breath

Question 3

expiratory reserve volume

Answer 3

max volume of air which can be expelled from lungs at end normal expiration

Question 4

inspiratory reserve volume

Answer 4

max volume air which can be drawn into lungs at end normal inspiration

Question 5

residual volume

Answer 5

volume of gas in lungs at end of maximal expiration

Question 6

vital capacity

Answer 6

tidal volume + inspiratory reserve volume + expiratory reserve volume

Question 7

total lung capacity

Answer 7

vital capacity + residual volume

Question 8

inspiratory capacity

Answer 8

tidal volume + inspirtatory reserve volume

Question 9

functional residual capacity

Answer 9

expiratory reserve volume + residual volume

Question 10

FEV1

Answer 10

forced expired volume in one second

Question 11

FEV1:FVC

Answer 11

fraction of forced vital capacity expired in one second

Question 12

pulmonary ventilation

Answer 12

total air movement into/out of lungs

kind of insignificant

Question 13

alveolar ventilation

Answer 13

fresh air getting to alveoli and available for gas exchange

Question 14

partial pressure

Answer 14

pressure of gas in a mixture of gases is equivalent to the percentage of that particular gas in the entire mixture multipled by pressure of the whole gaseous mixture

Question 15

P02 and PCO2 during hyperventilation

Answer 15

increased alveolar ventilation

PO2 rises
PCO2 falls

Question 16

P02 and PCO2 during hypoventilation

Answer 16

decreased alveolar ventilation

PO2 falls
PCO2 rises

Question 17

type 1 alveolar cells

Answer 17

thin walled cell that permits gas exchange

Question 18

type 2 alveolar cells

Answer 18

specialised cell that secretes surfactant

Question 19

surfactant

Answer 19

detergent-like fluid produced by T2 cells

reduce surface tension on alveolar surface membrane thus reducing tendency for alveoli to collapse

Question 20

what does surfactant do

Answer 20

increase lungs compliance
reduce lungs tendency to recoil
makes work breathing easier

Question 21

when is surfactant most effective

Answer 21

small alveoli because surfactant molecules come closer together and so are more concentrated

Question 22

when does surfactant production begin

what stimulates it

Answer 22

starts ~25wks gestation and completed ~36wks

stimulated by thyroid hormones and cortisol

Question 23

compliance

Answer 23

change in volume relative to change in pressure

represents stretchability of lungs (not elasticity)

Question 24

high compliance

Answer 24

large increase in lung volume for small decrease in ip pressure

Question 25

low compliance

Answer 25

small increase in lung volume for large decrease in ip pressure

Question 26

how does alveolar ventilation change from base to apex

Answer 26

alveolar ventilation declines with height from base to apex

Question 27

how does compliance change from base to apex

Answer 27

compliance declines with height from base to apex

Question 28

obstructive lung disease

Answer 28

obstruction of air flow, esp on expiration

Question 29

restrictive lung disease

Answer 29

restriction of lung expansion

Question 30

ex obstructive lung diseases

Answer 30

asthma

COPD

Question 31

ex restrictive lung diseases

Answer 31

fibrosis
IRDS
oedema
pneumothorax

Question 32

typical FEV1 value for fityoung male

Answer 32

4L

Question 33

typical forced vital capacity value young fit male

Answer 33

5L

Question 34

typical FEV1/FVC ration young fit male

Answer 34

80%

Question 35

spirometry of ostructive lung disease

Answer 35

FEV1 down

ratio down

Question 36

spirometry of restrictive lung disease

Answer 36

FEV1 and FVC down

ratio normal