Ventilation and Compliance 1

Question 1

What is anatomical dead space? What its its volume?

Answer 1

Volume of gas occupying the conducting airways.

~150ml

Question 2

What is residual volume?

Answer 2

The volume of air remaining after a peak expiration

Question 3

What is tidal volume?

Answer 3

Volume of air breathed in and out with each breath

Question 4

What is Expiratory Reserve Volume?

Answer 4

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

Question 5

What is Inspiratory Reserve volume?

Answer 5

The maximum volume of air which can be inspired after a normal inspiration

Question 6

What is Vital Capacity?

Answer 6

Tidal volume
Inspiratory Reserve volume
Expiratory reserve volume

Question 7

What is the total lung capacity?

Answer 7

Vital capacity and residual volume

Question 8

What is the Inspiratory capacity?

Answer 8

Tidal volume and inspiratory reserve volume

Question 9

What is the functional residual capacity/

Answer 9

Expiratory reserve volume and residual volume

Question 10

What is FEV1/FVC?

Answer 10

Fraction of forced vital capacity expired in one second

Question 11

What is pulmonary ventilation?

Answer 11

Total air movement into/out of lungs

Question 12

What is alveolar ventilation?

Answer 12

FRESH air getting to alveoli, therefore available for gas exchange (excluding anatomical dead space)

Question 13

What is partial pressure?

Answer 13

The percentage of a gas in the mixture x the pressure of whole mix

Question 14

What is the alveolar PO2?

Answer 14

13.3kPa

100mmHg

Question 15

What is the alveolar PCO2?

Answer 15

5.3kPa

40mmHg

Question 16

How do PO2 and PCO2 change during hyperventilation?

Answer 16

PO2 increases to 120mmHg

PCO2 decreases to 40mmHg

Question 17

How do PO2 and PCO2 change During Hypoventilation?

Answer 17

PO2 falls to 30mmHg

PCO2 increases to 100mmHg

Question 18

What type of cells make up alveolar walls?

Answer 18

Type 1 and 2 pneumocytes

Macrophages

Question 19

What is the role of surfactant?

Answer 19

Reduce surface tension on alveolar membrane?(makes breathing easier)

Question 20

Where does surface tension occur?

Answer 20

Air-water interface due to the attraction between water molecules

Question 21

What effect does surfactant have on compliance?

Answer 21

Increased compliance (easier to stretch the lungs)

Question 22

Where is surfactant most effective? Why?

Answer 22

Small alveoli

Smaller size means an increased concentration

Question 23

What does surfactant prevent?

Answer 23

Alveolar collapse

Question 24

What is compliance?

Answer 24

Change in volume relative to the change in pressure

Question 25

Why does initial inspiration require more pressure than later?

Answer 25

Tissue inertia and overcoming surface tension

Question 26

What effect does emphysema have on the work of respiration?

Answer 26

More effort due to loss of elasticity

Question 27

At end expiration, why are alveoli at the base less inflated than those at the apex?

Answer 27

The alveoli at the base of squashed by the weight of those above

Question 28

Where in the lung is compliance highest?

Answer 28

The base

Question 29

What is obstructive lung disease?

Answer 29

Obstruction of air flow, particularly on expiration

Question 30

What is restrictive lung disease

Answer 30

Restriction of lung expansion

Question 31

What is static spirometry?

Answer 31

Only consideration is the volume exhaled

Question 32

What is dynamic spirometry?

Answer 32

Time taken to exhale a certain volume

Question 33

What is a healthy FEV1/FVC?

Answer 33

80%

Question 34

What effect does obstructive lung disease have on FEV/FVC? Why?

Answer 34

Decrease

More effort needed to get the air out

Question 35

What is Forced Expiratory Flow?

Answer 35

The speed of air coming out in the middle of a forced expiration