Airway Resistance

Question 1

Reynold’s number

Answer 1

Predicts whether flow will be laminar or turbulent

Question 2

Formula for Reynolds number

Answer 2

Vpd/n

Question 3

Hagen poiselle eqn

Answer 3

/_\P.pie.r4/8.l.u

Question 4

Change in pressure equals

Answer 4

Flow x resistance

Therefore resistance varies inversely with fourth power of radius

Question 5

Which airways have the highest resistance

Answer 5

Medium sized airways

Question 6

Greatest resistance in?

Answer 6

Upper airways, first 7 generations

Question 7

In regulation of airway diameter, parasympathetic innervation…?

Answer 7

Mediates bronchoconztriction

Question 8

Sympathetic innervation?

Answer 8

Mediates bronchodilation,

Beta 2 adregenic receptors
Beta 2 agonists eg salbutamol/ salmeterol
Epinephrine

Why you should apply selective beta blockers to asthmatic pstirnyd bc it can block beta 2 receptors will will block respiratory airways

Question 9

Histamine in regulation of airways works how?

Answer 9

H1 stimulation leads to bronchoconstrivyion
H2 stilumayion leads to bronchodilation

You should not administer beta 2 blockers to asth

Question 10

Density of gas has no effect on resistance when airflow is..

Answer 10

Laminar

Question 11

Patients with upper airway obstruction have more

Answer 11

Turbulence than laminar flow
Heliox useful than regular air because it has low density and since density is important in turbulent flow and turbulent flow in upper airway extraction

Question 12

Volume flow rate equals

Answer 12

Cross sectional area × velocity

Area increases down tracheobronvhial trea. Velocity therefore drops since volume glow rate is nearly constant

Question 13

At generation 16/17 gas movement is by

Answer 13

Diffusion(terminal bronchioles and alveoli)

Question 14

Compliance is

Answer 14

Change is lung volume per unit pressure