Ventilation and Compliance

Question 1

What is the average total lung capacity?

Answer 1

6L

Question 2

What is tidal volume?

Answer 2

The volume of air breathed in and out when the person is breathing normally (500ml)

Question 3

What is residual volume?

Answer 3

The volume of air left in the lungs after expiration - cannot be breathed out

Question 4

Why do we have a residual volume left in our lungs after expiration?

Answer 4

It stops our alveoli collapsing

Question 5

What is the inspiratory reserve volume?

Answer 5

The maximum volume of air that can be breathed in

Question 6

What is the expiratory reserve volume?

Answer 6

The maximum volume of air that can be exhaled

Question 7

What is anatomical dead space?

Answer 7

The volume occupied by the conducting airways which is not available for gas exchange

Question 8

What is FEV1?

Answer 8

Forced expired volume in one second

Question 9

What is pulmonary ventilation?

Answer 9

The total air movement into and out of the lungs in L/min

Question 10

What is alveolar ventilation?

Answer 10

The fresh air getting to the alveoli and therefore available for gas exchange in L/min

Question 11

What is the partial pressure of the oxygen in the air we breathe in?

Answer 11

160 mmHg (21 kPa)

Question 12

What is the main role of surfactant

Answer 12

To reduce the surface tension on the alveolar surface membrane and reduce the tendency for the alveoli to collapse

Question 13

How does surfactant make breathing easier?

Answer 13

It increases lung compliance and reduces the lung’ s tendency to recoil

Question 14

Why is surfactant more effective in small alveoli compared to large alveoli?

Answer 14

In smaller alveoli the surfactant molecules are closer together and are therefore more concentrated

Question 15

What is compliance?

Answer 15

The change in volume relative to the change in pressure - the elasticity of the lungs

Question 16

What is the difference between obstructive and restrictive lung disease?

Answer 16

Obstructive is where there is an obstruction of the airflow especially on expansion.
Restrictive is when there is a restriction of lung expansion

Question 17

What lung disorders are classed as obstructive?

Answer 17

Asthma and COPD

Question 18

What lung disorders are classed as restrictive?

Answer 18

Fibrosis, Infant Respiratory Distress Syndrome, Oedema and Pneumothorax

Question 19

What are the two classifications of Spirometry?

Answer 19

Static (volume exhaled) and Dynamic (time taken to exhale a certain volume)

Question 20

What lung volumes can be directly measured by spirometry

Answer 20

Tidal volume, expiratory reserve volume, inspiratory reserve volume, inspiratory capacity and vital capacity

Question 21

What is the normal FEV1 in fit, healthy young adult males?

Answer 21

4L

Question 22

What is the normal FVC in fit, healthy young adult males?

Answer 22

5L

Question 23

What is the normal FEV1/FVC?

Answer 23

80%

Question 24

What happens to FEV1/FVC in someone with an obstructive lung disease

Answer 24

It decreases significantly

Question 25

What happens to FEV1/FVC in someone with a restrictive lung disease?

Answer 25

It may increase or stay the same (Both FEV1 and FVC drop significantly so the ratio stays roughly the same)

Question 26

At what stage during our development do we start producing surfactant?

Answer 26

Approx 25 weeks gestation (complete by approx 36 weeks)