respiratory 2

Question 1

to move gas into the lung, respiratory muscles overcome

Answer 1

• elastic resistance

- resistance to air flow (non elastic resistance)

Question 2

non-elastic resistance

Answer 2

airflow - 80%

viscous - 20%

Question 3

the ability to inflate and deflate the lung depends on two properties

Answer 3

compliance and elastance

Question 4

compliance

Answer 4

a highly compliant lung is easy to inflate
distensibility - stretchability - ease at which the lung will expand
lung is 100x more distensible than a balloon
pulmonary and/pr thoracic

Question 5

elastance

Answer 5

tendency to recoil to initial size after the distention

Question 6

elastance is created by

Answer 6

elastance proteins

- resist distension and cause recoil

Question 7

a lung that is highly complaint will tend to have

Answer 7

low elastance

Question 8

to be complaint we have to overcome

Answer 8

elastance

Question 9

surface tension

Answer 9

important at low lung volumes

• alveolar air-liquid interface
• inwardly directed force 0 tends to reduce alveolar diameter
• oppose alveolar expansion
• lung collapse (particularly in small alveoli)

Question 10

surfactant

Answer 10

lowers surface tension - reduces attractive forces of hydrogen bonding between H2O molecules

Question 11

surfactant is produced by

Answer 11

alveolar type 2 pneumocytes

Question 12

alveoli radius

Answer 12

small alveoli generate more surface tension

as alveolar radius decreases, surfactants ability to lower surface tension increases

Question 13

why might we want smaller alveoli

Answer 13

to increase surface area

Question 14

what do we do to reduce surface tension

Answer 14

line the alveoli with surfactant secreted by type 2 pneumocites

Question 15

what happens when there is no surfactant

Answer 15

lack of surfactant creates huge surface tension requiring high expansion pressures

Question 16

infant respiratory distress syndrome

Answer 16

premature birth

surfactant not produces at high levels until 34 weeks gestation so some very preterm babies don’t have enough surfactant

Question 17

low compliance lung

Answer 17

stiff lung

extra work required for normal inspiration

Question 18

low compliance lung may be caused by

Answer 18

fibrosis - decrease in pulmonary compliance

Question 19

high compliance lung

Answer 19

floppy lung
extra work is required for expiration
elastic tissue is damaged

Question 20

non-elastic resistance

Answer 20

35%

Question 21

airway resistance

Answer 21

depends on the diameter

as airways get smaller this increases

Question 22

mucous resistance

Answer 22

depends how much mucous there is in the transmitting pathways
increased in response to histamine (histamine increases mucous secretions and viscosity)

Question 23

histamine receptors

Answer 23

HIR - volume

H2R - viscosity

Question 24

mucosal oedema

Answer 24

release of fluid from the blood into the lungs

caused by increase in permeability leading to transduction of fluid and macromolecules through wide intercellular gaps

Question 25

chronic bronchitis

Answer 25

too much mucous produced by the lungs

Question 26

cystic fibrosis

Answer 26

CFTR mutation chloride channel loss of ability too regulate chloride loss which changes osmotic gradient and affects mucous production

Question 27

bronchodilation

Answer 27

B2-adrenergic receptor activation | mostly endocrine but some nervous

Question 28

bronchoconstriction

Answer 28

muscarinic cholinergic re emptor activation | also histamine H1 receptor

Question 29

bronchomotor tone

Answer 29

parasympathetic tone controls bronchomotor tone | increase in parasympathetic tone increases acetyl choline produced and vice versa

Question 30

other local effects controlling acetylcholine reflex constriction

Answer 30

inhalation of smoke, dust, chemical irritants arterial hypercapnia cold pulmonary emboli

Question 31

bronchodilator endocrine

Answer 31

adrenaline causes bronchodilator using b2 adrenergic receptor beta agonists cause bronchodilation beta antagonists cause bronchoconstriction

Question 32

measuring R

Answer 32

hard to measure resistance directly | measure its effects on function instead

Question 33

PEF

Answer 33

peak expiratory flow

Question 34

FEV1

Answer 34

forced expiratory volume in one second

Question 35

FEV1/FVC

Answer 35

FEV/forced vital capacity

Question 36

FVC

Answer 36

forced vital capacity | how much air can be taken out of fully inflated lung

Question 37

3 main things causing respiratory disease

Answer 37

- respiratory muscles fail - restrictive disease decreases compliance - obstructive disease increases resistance

Question 38

restrictive lung disease

Answer 38

decreases compliance decreases lung volume limits expansion decrease in flow and ventilation causing increase in work required

Question 39

obstructive lung disease

Answer 39

increase in resistance flow rate is decreased increase in work required to overcome resistance to flow decreased ein airflow causes increase n respiratory times

Question 40

restrictive lung disorder stats

Answer 40

decreased vital capacity, residual volume, functional residual capacity

Question 41

obstructive lung disorders

Answer 41

decreased vital capacity, inspiratory and expiratory reserve volume increased residual volume, functional residual capacity, RV/TLC,

Question 42

obstructive complications

Answer 42

increased resistance to airflow due to abnormalities within the airway lumen changes in the wall of the airway decrease in elastic recoil

Question 43

obstructive complications examples

Answer 43

asthma, chronic obstructive lung disease bronchiectasis cystic fibrosis bronchiolitis

Question 44

restrictive defects are caused by

Answer 44

- loss of lung volume - abnormalities of structure surrounding the lung - weakness of the inspiratory muscles of respiration - abnormalities of the lung parenchyma

Question 45

parenchymal

Answer 45

``` sarcoidosis - fibrosis idiopathic pulmonary fibrosis pneumonia, pulmonary oedema drug or radiation induced interstitial lung disease ```

Question 46

extraparenchymal

Answer 46

myasthenia gravis - Guillain-barre syndrome, muscular dystrophies diaphragmatic weakness/paralysis chest wall, kyphoscoliosis

Question 47

normal FEV1/FVC

Answer 47

80%

Question 48

normal flow-volume loop

Answer 48

inspiratory is symmetric and convex | expiratory limb is linear

Question 49

obstructive flow volume loop

Answer 49

peak expiratory flow is reduced increased residual volume FEV1/FVC reduced

Question 50

restrictive flow volume loop

Answer 50

reduction in total lung capacity | FEV1/FVC reduced