Airway dynamics

Question 1

2 ways airways can be decreased

Answer 1

1. smooth muscles

2. edema

Question 2

at what point does airway area signifacntly increase

Answer 2

after 10 generation

Question 3

2 drug types that can dilate and constrict lungs

Answer 3

1. beta blockers -constrict ,agonists dilate

2. parasymp antagonists - constrict

Question 4

2 main types of flow

Answer 4

1. laminar

2. tubulent

Question 5

features of laminar flow

Answer 5

orderly
lowresitance
assymetric

Question 6

features of turbulent flow

Answer 6

disorganized

higher resitance

Question 7

what type of flow is generally present in small airways

Answer 7

laminar

Question 8

what is pressure drop along a tube proportional to in laminar vs. turbulent flow

Answer 8

laminar - equal to flow rate

turbulent - 4 times the flow rate

Question 9

what is more important in tubulent flow, viscosity or density

Answer 9

density

Question 10

what is formula to determine flow type

Answer 10

Reynolds number
Re = 2rvd/viscosity
if >2000 – turbulent

Question 11

what is more important in laminar flow, viscosity or density

Answer 11

viscosity

Question 12

what will lower density favor

Answer 12

laminar flow

Question 13

what is a method of lowering desnity and therefore creating laminar flow

Answer 13

give He

Question 14

what size airway s site of major airway resitance

Answer 14

medium sized

Question 15

why is med size the point of major resitance

Answer 15

smaller diameter, but not branched enough to create parallel lowering

Question 16

at what lung volume is resistance lowest?

Answer 16

higher volumes -> pt. with resisitance breathe at higher volumes

Question 17

where in a flow volume curve is effort dependant

Answer 17

first half - is dependant, second half is independant

Question 18

what does the alveolar pressure equal

Answer 18

the elastic recoil pressure plus the pleural pressure

Question 19

what will cause the airway to collape (2)

Answer 19

1. increase airway resistance

2. decrease elastic recoil

Question 20

what will be seen of F/V curve with upper airway narrowing

Answer 20

flattening in exp and inspiratory loop

Question 21

what will happen if obstruction is intrathoracic

Answer 21

neg. pleural pressure will open airway on inspiration, but close it on expiration

Question 22

what will happen in extrathoracic obstruction

Answer 22

no effect of pleuraal pressure