airway resistance

Question 1

Answer 1

Question 2

what disease is work of breathing increased in

Answer 2

both restrictive and obstructive diseases

Question 3

define work of breathing

Answer 3

energy used to inhale and exhale

Question 4

equation for work or breathing

Answer 4

W = P x V

(pressure x volume)

Question 5

% cost of O2 consumption during:

-quiet breathing at rest
-hyperventilation
-obstructive lung disease

Answer 5

5%
30%
very high

Question 6

what holds an airway open

Answer 6

pressure difference across the airway (except during forced expiration)

Question 7

dynamic compression of airways occurs when

Answer 7

during forced expiration

Question 8

what is flow determined by during dynamic compression

Answer 8

alveolar pressure minus intrapleural pressure

(not armospheric pressure)

Question 9

how does COPD exaggerate the dynamic compression of airways

Answer 9

increase in resistance of peripheral airways

Question 10

how does emphysema exaggerate the dynamic compression of airways

Answer 10

reduced lung elastic recoil & loss of radial traction on airways

Question 11

what is the location of the MOST airway resistance in the respiratory system

Answer 11

at the medium-sized bronchi

Question 12

poiseuille’s law for resistance equation

Answer 12

R: resistance
n: viscosity
l: length
pi: 3.14
r: radius

Question 13

reducing radius (r) by 50% will increase flow (R) by how much

Answer 13

16-fold