Physiology 2

Question 1

What is the tidal volume and average value?

Answer 1

• The volume of air entering or leaving the lungs during a single breath
• 500 ml

Question 2

What is the inspiratory reserve volume and average value?

Answer 2

• The extra volume of air that can be maximally inspired over and above the typical resting tidal volume
• 3000 ml

Question 3

What is the inspiratory capacity and average value?

Answer 3

• Maximum volume of air that can be inspired at the end of a normal quiet expiration.
• 3500 ml

Question 4

How is Inspiratory capacity related to inspiratory reserve volume and tidal volume?

Answer 4

IC= IRV + TV

Question 5

What is the expiratory reserve volume and average value?

Answer 5

• The extra volume of air that can be actively expired by maximal contraction beyond the normal volume of air after a resting tidal volume
• 1000 ml

Question 6

What is the residual volume and average value?

Answer 6

• Minimum volume of air remaining in the lungs even after a maximal expiration
• 1200 ml

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Question 7

What is the functional residual capacity and average value?

Answer 7

• The volume of air in the lungs at the end of a normal passive expiration
• 2200 ml

Question 8

How is functional residual capacity related to expiratory reserve volume and residual volume

Answer 8

FRC= ERV + RV

Question 9

What is vital capacity and average volume?

Answer 9

• Maximum volume of air that can be moved out during a single breath following a maximal inspiration
• 4500 ml

Question 10

How is vital capacity related to Inspiratory reserve volume, tidal volume and expiratory reserve volume?

Answer 10

VC= IRV + TV + ERV

Question 11

What is total lung capacity and average volume?

Answer 11

• maximum volume of air that the lungs can hold.

- 5700 ml

Question 12

How is total lung capacity related to vital capacity and residual volume?

Answer 12

TLC= VC + RV

Question 13

What is the forced expiratory volume in one second (FEV1): Dynamic volume

Answer 13

The volume of air that can be expired during the first second of an expiration in an FVC determination

Question 14

What is the FEV1%?

What is the normal value?

Answer 14

The FEV1/FVC ratio

Normal value >75%

Question 15

What values can be determined from a volume time curve? (3)

Answer 15

The FVC, FEV1 and FEV1%

Question 16

What are the FVC, FEV1 and FEV1/FVC values in normal spirometry

Answer 16

FVC: Normal
FEV1: Normal
FEV1%: Normal

Question 17

What are the FVC, FEV1 and FEV1/FVC values in airway obstruction?

Answer 17

FVC: Low or normal
FEV1: Low
FEV1%: Low

Question 18

What are the FVC, FEV1 and FEV1/FVC values in lung restriction?

Answer 18

FVC: Low
FEV1: Low
FEV1%: Normal

Question 19

What are the FVC, FEV1 and FEV1/FVC values in a combination of obstruction and restriction?

Answer 19

FVC: Low
FEV1: Low
FEV1%: Low

Question 20

What is the formula for airway resistance (Flow)

Answer 20

Flow= Change in pressure/Resistance

Question 21

What effect does the parasympathetic branch of the autonomic nervous system have on bronchial smooth muscle?

Answer 21

Bronchoconstriction

Question 22

What effect does the sympathetic branch of the autonomic nervous system have on bronchial smooth muscle?

Answer 22

Bronchodilation

Question 23

What are the accessory muscles of inspiration? (2)

Answer 23

Sternocleidomastoid

Scalenues

Question 24

What are the muscles of active expiration?

Answer 24

Internal intercostal muscles

Abdominal muscles

Question 25

How are the airways held open by dynamic airway compression?

Answer 25

Increase in airway pressure upstream Airways opened by increasing driving pressure between the alveolus and airway (Pressure downstream)

Question 26

How does an airway obstruction (COPD or asthma) affect driving pressure between alveolus and airway?

Answer 26

Driving pressure between alveolus and airway is lost over obstructed segment Fall in airway pressure downstream--> Airway collapse caused by rising pleural pressure during active expiration.

Question 27

What does peak flow rate assess?

Answer 27

Airway function

Question 28

What is peak flow useful in diagnosis of?

Answer 28

Obstructive diseases

Question 29

What is pulmonary compliance?

Answer 29

The effort that has to go into stretching or distending the lungs. Less compliance= More work require to inflate lungs

Question 30

Name some factors that cause decreased pulmonary compliance. (5)

Answer 30

- Pulmonary fibrosis - Pulmonary oedema - Lung collapse - Pneumonia - Absence of surfactant

Question 31

How does emphysema relate to pulmonary compliance?

Answer 31

Abnormally increased pulmonary compliance. Patients have to work harder to get air out of the lungs.

Question 32

What factors cause work of breathing to increase?

Answer 32

- When pulmonary compliance is increased - When airway resistance is increased - When elastic recoil is decreased - When there is need for increased ventilation