3. Ventilation and Compliance

Question 1

What is anatomical dead space?

Answer 1

Volume of gas occupied by the conducting airways and this gas is not available for gas exchange - 150 ml

Question 2

What is the inspiratory reserve volume? (IRV)

Answer 2

The maximum volume of air which can be drawn into the lungs at the end of a normal inspiration
3000ml

Question 3

What is the volume of air at the start of normal inspiration?

Answer 3

2300

Question 4

What is tidal volume?

Answer 4

The 500ml that we breath in with every breath at rest

Question 5

What is residual volume?

Answer 5

The volume of air we can’t expel from our lungs - holds alveoli open (even after maximal respiration) - 1200 ml

Question 6

What is the functional residual capacity?

Answer 6

Expiratory reserve volume + residual volume.

Question 7

What is a capacity?

Answer 7

Two or more volumes added together

Question 8

What is vital capacity?

Answer 8

Tidal volume + inspiratory reserve volume + expiratory reserve volume

Question 9

What is the maximum volume of air a pair of lungs can hold?

Answer 9

5800ml

Question 10

What is pulmonary (Minute) ventilation?

Answer 10

Total air movement into/out of lungs (relatively insignificant in functional terms)

Question 11

What is Alveolar ventilation ?

Answer 11

Fresh air getting to alveoli and therefore available for gas exchange (functionally much more significant!)

Question 12

DIAGRAM

Answer 12

.

Question 13

Will someone who is anxious have a higher or lower tidal volume?

Answer 13

Lower but faster respiratory rate

Question 14

How do you calculate air to alveoli?

Answer 14

Tidal - dead space

Question 15

What is the main factor that affects the aeriolar ventilation?

Answer 15

The depth of the breadth, rather than the respiratory rate, because of the influence of the dead space volume.

Question 16

What is hyperventilation?

Answer 16

Increased ventilation - concerns depth and not frequency of breathing

Relaxed is hyperventilating

Question 17

What is partial pressure?

Answer 17

Definition:The pressure of a 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 18

What measurement of pressure do clinicians use?

Answer 18

Kilopascals (kPa)

Question 19

What is another measurement of pressure that isn’t kilopascals?

Answer 19

Millimetres mercury mmHg

Question 20

What is atmospheric pressure?

Answer 20

760mmHg (101kPa)

Question 21

What is normal alveolar ventilation?

Answer 21

4.2 litres/minute

Question 22

Why is the alveolar partial pressure less than atmospheric partial pressure?

Answer 22

Inefficiency of breathing - dead space dilutes the amount of oxygen

Residual volume - dilutes the amount of oxygen

Water is added - displaces some of the oxygen

Question 23

What is the partial pressure of the atmosphere?

Answer 23

160 mmHg

Question 24

What is expiratory reserve volume?

Answer 24

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

Question 25

What is the total lung capacity?

Answer 25

The vital capacity plus the residual volume

Question 26

What is the inspiratory capacity?

Answer 26

Tidal volume + inspiratory reserve volume.

Question 27

What does FEV1 stand for?

Answer 27

Forced Expired Volume in 1 second

Question 28

what does FEV1:FVC stand for?

Answer 28

Fraction of Forced Vital Capacity expired in 1 second

Question 29

What is the fluctuation of PO2 and PCO2 like under normal resting conditions?

Answer 29

PO2 and PCO2 remain fairly constant

Question 30

What happens to PO2 and PCO2 during hyper-ventilation (increased alveolar ventilation)?

Answer 30

PO2 rises to about 120 mm Hg and PCO2 falls to about 20 mmHg

Question 31

What happens to PO2 and PCO2 during hypo-ventilation (decreased alveolar ventilation)?

Answer 31

PO2 falls to 30 mmHg and PCO2 rises to 100 mmHg