Lecture 3: Airway Resistance & Pulmonary Compliance

Question 1

airway resistance is normally very ___

Answer 1

small

Question 2

changes in airways resistance are brought about by changes in ___ of the airways by ____ of smooth muscles of the airways

Answer 2

radius; contraction

Question 3

airway radius may change due to ___, ___ or ___ factors

Answer 3

physical, neural, chemical

Question 4

resistance is the opposition to ____

Answer 4

motion

Question 5

the flow of air into the lungs is ___ proportional to resistance for laminar flow

Answer 5

inversely

Question 6

in astma, airway smooth muscle constricts and causes __- and ____

Answer 6

higher airway resistance and more work to breathe

Question 7

airway resistance is primarily determined by the ___ of the airways

Answer 7

radius

Question 8

air flow is ___ proportional to pressure difference between atmosphere and alveoli

Answer 8

directly

Question 9

what is the major site of airway resistance in the airways?

Answer 9

large. bronchi

Question 10

in the conducting zone, airflow velocity ___- substantially as the effective cross-sectional area increase

Answer 10

decrease

Question 11

in the respiratory zone, airway generations exist in ___ rather than in series

Answer 11

parallel

Question 12

what are the 4 factors that contribute to airway resistance

Answer 12

1. lung volume
2. viscosity
3. autonomic nervous sytem
4. other agents

Question 13

what is the effect of increasing lung volume on air resistance?

Answer 13

increases airways diameter, so decreases resistance

Question 14

the relationship between the reciprocal of resistance (conductance) and volume is ___

Answer 14

linear

Question 15

what is the effect of increased air viscosity on airway resistance>

Answer 15

increases pressure and resistance

Question 16

breathing ___ viscosity air, such as a mix of O2 with __-, decreases resistance and can be used as treatment for ___

Answer 16

low; He; status asthmaticus

Question 17

what is the effect of parasympathetic activation on airway resistance?

Answer 17

constriction of airways and more resistance

Question 18

what is the effect of sympathetic activation on airway resistance?

Answer 18

relaxation of B2 receptors, decreases resistance

Question 19

B2 agonists are useful in treatment of ____ (ex of drug: ___)

Answer 19

asthma; albuterol

Question 20

histamine, Ach, TxA2, leukotrienes etc are released in response to triggers (allergies, viral infections etc) and cause what effect on airway resistance?

Answer 20

bronchoconstriction; increased resistance

Question 21

____ is characterized by increased responsiveness of the airways to various stimuli

Answer 21

asthma

Question 22

astma manifests as widespread ___ of the airways

Answer 22

narrowing

Question 23

what are 4 symptoms of asthma?

Answer 23

1. excess mucus secretion
2. chronic inflammation
3. chest tightening
4. coughing / wheezing

Question 24

asthma affects ~____ people worldwide and causes ____ deaths annually

Answer 24

300 million; 250 thousand

Question 25

lung compliance refers to __

Answer 25

how easy it is for the lung to expand

Question 26

the ____ the compliance, the easier it is for the lungs to expand at any given change in Ptp

Answer 26

greater

Question 27

in ___ there is destruction of the lung tissue so lungs are unable to spring back after inspiration. In this case, the compliance is too ____

Answer 27

emphysema; great

Question 28

the ___ the compliance, there is a lesser increase in lung volume for any given increase in Ptp

Answer 28

lower

Question 29

in ____, the deposition of collagen fibres into the lungs results in thickened, scar-tissue around the alveoli, making it harder to expand the lungs. In this case, the compliance is too ___

Answer 29

fibrosis; low

Question 30

emphysema is also called ___

Answer 30

floppy lungs

Question 31

fibrosis is also called ___

Answer 31

stiff lungs

Question 32

compliance is the inverse of ____ (the ability to regain original shape after distension or compression)

Answer 32

elactance

Question 33

emphysema is classed as a ____ disease

Answer 33

obstructive

Question 34

why is emphysema classed as an obstructive disease?

Answer 34

because the conducting airways will collapse due to loss of surrounding support tissue

Question 35

pulmonary fibrosis is classed as a ____ disease

Answer 35

restrictive

Question 36

why is pulmonary fibrosis classed as a restrictive disease?

Answer 36

because there is a restriction to the normal movement of air into the lungs

Question 37

lung volume depends on what 2 things?

Answer 37

1. transpulmonary pressure | 2. compliance of lung tissue

Question 38

what are the 2 major determinants of compliance?

Answer 38

1. stretchability of lung tissue | 2. surface tension at the air-liquid interface in alveoli

Question 39

the surface tension at the air-liquid interface of the alveoli is decreased by ___

Answer 39

surfactant

Question 40

____ is deficient in respiratory distress syndrome of the newborn

Answer 40

surfactant

Question 41

lungs inflated with ___ have much higher compliance compared to air-filled lungs

Answer 41

saline

Question 42

difference between air and liquid filled lungs is due to ____

Answer 42

surface tension forces

Question 43

why does a lung full of saline have higher compliance than air-filled lung?

Answer 43

saline abolishes the surface tension forces without affecting tissue forces q

Question 44

compliance is measured on the ____ limb

Answer 44

expiration

Question 45

what would happen if there were pressure differences between alveoli?

Answer 45

air would move to low pressure system and alveolus with the larger pressure would collapse

Question 46

in smaller alveoli, molecules of surfactant are ___ in relation to each other, which decreases_____ more than in larger alveoli

Answer 46

closer; surface tension forces

Question 47

what is responsible for stabilizing pressure in the alveoli?

Answer 47

surfactant

Question 48

what is surfactant made of ?

Answer 48

mix of proteins and phospholipids

Question 49

what cells secrete surfactant?

Answer 49

type 2 alveolar cells

Question 50

surfactant ___ lung compliance

Answer 50

increases

Question 51

secretion of surfactant is increased by ____

Answer 51

taking a large breath that will stretch type 2 alveolar cells

Question 52

type 2 alveolar cells are not made until the ___ week pf pregnancy

Answer 52

24

Question 53

babies with RDSN have to work harder to breathe due to ___ compliance

Answer 53

decreased

Question 54

if a mother is going into premature labour (24 weeks or before), what can be given to them to increase their babies alveolar 2 activity?

Answer 54

corticosteroids

Question 55

wha can be given to a baby after birth to better their breathing?

Answer 55

exogenous surfactant