3.Ventilation and Compliance 1

Question 1

what volume does anatomical dead space occupy approximately?

Answer 1

approx. 150ml

Question 2

what is anatomical dead space?

Answer 2

volume of gas occupied by the conducting airways (trachea/bronchi) and this gas is NOT available for gas exchange

Question 3

What is the tidal volume (TV)?

Answer 3

volume of air breathed in and out of the lungs at each breath

Question 4

what is the approx. volume of tidal volume (TV) in ml at each breath?

Answer 4

500ml

Question 5

What is the Expiratory reserve volume (ERV)?

Answer 5

the maximum volume of air which can be expelled from the lungs at the end of a normal expiration

Question 6

what is the approx. volume of expiratory reserve volume (ERV) in ml which can be expired?

Answer 6

1100ml

Question 7

What is the Inspiratory Reserve Volume (IRV)?

Answer 7

the maximum volume of air which can be drawn into the lungs at the end of a normal inspiration

Question 8

what is the approx. volume of inspiratory reserve volume (IRV) in ml which can be inspired?

Answer 8

3000ml

Question 9

What is the residual volume (RV)?

Answer 9

the volume of gas in the lungs at the of of a normal expiration

Question 10

what is the approx. value of residual volume (RV) in ml in the lungs?

Answer 10

1200ml

Question 11

what is the Vital Capacity (VC)?

Answer 11

tidal volume + inspiratory reserve volume + expiratory reserve volume

Question 12

what is the Total Lung Capacity (TLC)?

Answer 12

vital capacity + residual volume (the WHOLE volume of lungs)

Question 13

what is the approximate value of the Vital Capacity (VC) volume in ml in the lungs?

Answer 13

4600ml

Question 14

what is the Inspiratory Capacity (IC)?

Answer 14

tidal volume (TV) + inspiratory reserve volume (IRV)

Question 15

what is the Functional Residual Capacity? (FRC)

Answer 15

expiratory reserve volume + residual volume

Question 16

what is FEV1: FVC?

Answer 16

fraction of forced vital capacity expired in 1 second

Question 17

is pulmonary ventilation the same as alveolar ventilation?

Answer 17

NO

Question 18

What is pulmonary ventilation?

Answer 18

total air movement into/out of lungs (it’s relatively insignificant in functional terms)

Question 19

what is alveolar ventilation?

Answer 19

FRESH air getting into alveoli and therefore available for GAS EXCHANGE (functionally more significant)

Question 20

what units are used to measure both pulmonary ventilation and alveolar ventilation?

Answer 20

L/min

Question 21

what term describes decreased alveolar ventilation occurring in the lungs (less than normal)? Who could be affected?

Answer 21

hypoventilation; e.g. an anxious/panicky/nervous patient

Question 22

what term describes increased alveolar ventilation occurring in the lungs (more than normal)? Who could be affected?

Answer 22

hyperventilation; e.g.a very relaxed person on holiday

Question 23

what is the NORMAL tidal volume? (ml)

Answer 23

500ml

Question 24

what is the NORMAL respiratory rate? (breaths/minute)

Answer 24

12-18 normal

Question 25

what is the total pulmonary ventilation (ml/min) in normal and abnormal ventilation?

Answer 25

6000

Question 26

How many ml of air to alveoli is there in normal ventilation (tidal- dead space)?

Answer 26

350ml

Question 27

what is the alveolar ventilation (ml/min) in normal ventilation?

Answer 27

4200ml/min

Question 28

why is the total pulmonary ventilation (ml/min) the same for a normal, hypoventilating and hyperventilating person? (600ml/min)

Answer 28

because to measure total pulmonary ventilation= tidal volume x respiratory rate which will bring it to 6000 in the end eg. in a hypoventilating patient, tidal volume will be smaller yet resp. rate will be quicker (more rapid breaths to make up for less oxygen) so in the end it will produce a total pulmonary ventilation of 6000 .- the opposite for hyperventilating patient (where less breaths need to be taken as TV is so high it can last a longer time)

Question 29

what tidal volume and respiratory rate is considered to be hypoventilation?

Answer 29

350ml for TV | approx. 20 breaths/min (rapid)

Question 30

what tidal volume and respiratory rate is considered to be hyperventilation?

Answer 30

750ml for TV | approx. 8 breaths/min (slow)

Question 31

Out of normal, hypoventilating and hyperventilating patients, who will have the most air (ml) to alveoli and in the end more alveolar ventilation (ml)? list from highest to lowest

Answer 31

1. hyperventilating patient (most ml) 2. normal patient 2. hypoventilating patient

Question 32

Define partial pressure

Answer 32

The pressure of gas in a mixture of gases is equivalent to the percentage of that particular gas in the entire mixture, multiplied by the pressure of the whole gaseous mixture.

Question 33

what 2 units are used to express pressure?

Answer 33

mmHg and kPA

Question 34

what is the most important pressure rule when speaking about gas pressure?

Answer 34

All gas molecules exert the SAME pressure (so partial pressure increases with increasing conc. gas mixture)

Question 35

Under normal conditions, do resting PO2 and PCO2 remain fairly constant?

Answer 35

Yes, they do

Question 36

what varies alveolar PO2 and PCO2?

Answer 36

hyperventilation and hypoventilation

Question 37

What happens to PO2 and PCO2 during hyperventilation

Answer 37

- PO2 rises to around 120mmHg | - PCO2 falls to around 20mmHg

Question 38

What happens to PO2 and PCO2 during hypoventilation?

Answer 38

- PO2 falls to around 30mmHg | - PCO2 rises to around 100mmHg

Question 39

What is the "normal" ventilation in L/min?

Answer 39

4.2L/min