Physiology: airway resistance, dynamic airway compression & peak flow

Question 1

what is the primary determinant of airway resistance

Answer 1

radius of conducting airway

Question 2

what does parasympathetic stimulation of airways cause

Answer 2

bronchoconstriction

Question 3

what does sympathetic stimulation of airways cause

Answer 3

bronchodilatation

Question 4

what effect does dynamic airway compression have in patients with obstructive airway conditions

Answer 4

makes active expiration more difficult, due to airway compression by the rising pleural pressure

Question 5

what does a peak flow meter measure

Answer 5

peak flow rate

Question 6

what does peak flow rate assess

Answer 6

airway function

Question 7

what patients is peak flow rate useful for

Answer 7

obstructive airway conditions(e.g COPD, asthma)

Question 8

in dynamic airway compression, what effect does increased airway resistance cause in normal people

Answer 8

causes increased airway pressure upstream

Question 9

how does dynamic airway compression help open the airways of normal people

Answer 9

by increasing the driving pressure between the alveolus and the airway(i.e. the pressure downstream)