Static Mechanisms

Question 1

distending pressure across lung aka

Answer 1

transpulmonary pressure

Question 2

what is the transpulmonary pressure

Answer 2

difference in pressure between the outside and inside of lung = Alveolar -intrapleural pressures

Question 3

distensibility aka

Answer 3

compliance

Question 4

what is lung compliance?

Answer 4

change in volume of lung produced per unit distending pressure

Question 5

what two factors account for retractive or recoil force of lung?

Answer 5

elastic tissue and surface forces

Question 6

lung recoil depends on surface tension at –

Answer 6

alveolar air-fluid interface

Question 7

lung recoil depends on – in alveolar walls and bronchi

Answer 7

elastic and collagen fibers

Question 8

without surfactant, recoil forces would be –

Answer 8

more powerful

Question 9

without surfactant, lung ventilation would be –

Answer 9

more difficult

Question 10

function of surfactant

Answer 10

reduce surface tension and lung recoil

Question 11

surfactant is a – material that is rich in phospholipid dipalmitol lecithin

Answer 11

lipoprotein

Question 12

surfactant is synthesized in –

Answer 12

type II alveolar cells

Question 13

where is surfactant extruded?

Answer 13

alveoli surface

Question 14

surfactant – the tendency of smaller alveoli to empty in larger ones

Answer 14

counter

Question 15

surfactant prevents – into alveoli from pulmonary capillaries

Answer 15

transudation of fluid

Question 16

when is surfactant formed?

Answer 16

late in fetal life

Question 17

in premature births, insufficient surfactant is available or inactive which leads to –

Answer 17

neonatal respiratory distress syndrome = stiff lungs, collapsed alveoli

Question 18

reduced lung elastic recoil –> chest wall moves –

Answer 18

out

Question 19

increased lung elastic recoil –> chest wall moves –

Answer 19

in

Question 20

At residual volume, elastic recoil of chest wall is directed outward is –

Answer 20

large (inward is small)

Question 21

at functional residual capacity, elastic recoils of lung and chest are –

Answer 21

equal but opposite

Question 22

at larger lung volume, elastic recoil of chest wall becomes – and recoil of lung –

Answer 22

recoil of chest wall decreases and recoil of lung increases

Question 23

at approximately 70% of total lung capacity, equilibrium position of – (its recoil is 0)

Answer 23

chest wall

Question 24

at total lung capacity, elastic recoil of both lung and chest wall directed – favoring a decrease in lung volume

Answer 24

inward

Question 25

normal lung at rest: recoils

Answer 25

chest wall outward and lung inward

Question 26

how accommodating?

Answer 26

compliance

Question 27

compliance

Answer 27

change in volume/change in pressure

Question 28

how stiff?

Answer 28

elastance

Question 29

elastance

Answer 29

change in pressure/change in volume

Question 30

Law of LaPlace, if two bubbles have the same surface tension, the small bubble will have the –pressure

Answer 30

higher

Question 31

surfactant reduces surface tension so it – pressure in large and small bubbles

Answer 31

equalizes