respiratory system 1

Question 1

lung compliance

Answer 1

distensibility of the lungs

Question 2

what does a spirometer measure

Answer 2

lung volumes

Question 3

what does an oesophageal balloon measure

Answer 3

pleural cavity pressure

Question 4

what is the balloon for in an oesophageal balloon

Answer 4

to prevent mucosa from blocking the catheter tip

Question 5

equation for lung compliance

Answer 5

C=(delta)V / (delta)P

slope of volume v pressure graph
slope is taken at the steepest point which occurs at FRC

Question 6

what allows alveolar walls to stretch

Answer 6

elastic fibres and surface tension

Question 7

what is hysteresis

Answer 7

the difference in pressure volume plot between inflation and deflation

Question 8

how does pulmonary fibrosis effect lung compliance

Answer 8

it decreases it as alveoli become stiffened due to collagen formation

Question 9

what is obstruction

Answer 9

narrowing of the airways

Question 10

restrictive ventilatory defect

Answer 10

restriction of lung volumes

Question 11

what is minute volume (equation)

Answer 11

minute volume= tidal volume x respiratory rate

Question 12

what lung measurement is preserved the longest during disease and why

what occurs to all other volumes

Answer 12

minute volume as it is essential in maintenance of blood gases

they decrease

Question 13

what is the preferred lung volume to be measured to diagnose restriction

Answer 13

total lung capacity

Question 14

what is the clinical significance of restrictive ventilatory defect

Answer 14

the work of breathing will increase as increased load will be felt by the respiratory muscles to breathe a normal minute volume (patients will complain of dyspnoea)

Question 15

what is functional residual capacity

Answer 15

the volume of air in the lungs at the end of quiet expiration

Question 16

how does lung restriction effect functional residual capacity

why

Answer 16

lower FRC as to reduce the work of breathing because the load on the respiratory muscles is decreased when stiff lungs are under less stress

Question 17

type 1 respiratory failure

Answer 17

hypoxemia

low pO2 normal pCO2

damage to lung tissue which prevents adequate oxygenation of the blood

Question 18

type 2 respiratory failure

Answer 18

hypoxia & hypercapnia

low pO2 high pCO2

occurs when alveolar ventilation is insufficient to excrete the carbon dioxide being produced and introduce new oxygen

Question 19

does hypoxia cause vasoconstriction or vasodilation of pulmonary arteries

Answer 19

vasoconstriction (in contrast to systemic vessels which dilate)

this diverts blood from poorly oxygenated regions

Question 20

pulmonary oedema

Answer 20

excess fluid in the lungs most usually caused by heart problems

Question 21

bronchiectasis

Answer 21

abnormal widening of the bronchi or their branches, causing a risk of infection

Question 22

pneumothorax

Answer 22

a collapsed lung
occurs when air leaks into the space between your lung and chest wall
this air pushes on the outside of your lung and makes it collapse
a pneumothorax can be a complete lung collapse or a collapse of only a portion of the lung

Question 23

what is silent chest in asthma

Answer 23

the airways are so constricted that even a wheeze can’t be heard

Question 24

pulmonary fibrosis

Answer 24

replacement of elastin fibres with collagen fibres

Question 25

does pulmonary fibrosis < or > lung compliance?

Answer 25

decrease

Question 26

emphysema

Answer 26

elastin fibres are destroyed by enzymes rather than replaced

Question 27

does emphysema < or > lung compliance

Answer 27

increase (so NOT a restrictive defect- it is obstructive)

Question 28

2 causes of emphysema

Answer 28

1. cigarette smoking which causes activation of elastase release from inflammatory cells. elastase is the enzyme that destroys elastic fibres
2. a rarer cause is the congenital disease alpha 1- anti trypsin deficiency

Question 29

respiratory distress syndrome

Answer 29

surfactant deficiency

Question 30

who often gets respiratory distress syndrome

Answer 30

premature babies

adults in intensive care

Question 31

what is peak flow measurement used for

Answer 31

to monitor obstructive airway diseases (units are L/min)

Question 32

what does spirometry measure

Answer 32

measures the volume of gas exhaled and the rate of exhalation during a forced expiratory manoeuvre

Question 33

FVC

Answer 33

volume of air subject can eject from full lungs during maximal expiration after full inspiration

Question 34

FEV1

Answer 34

volume of air that can be ejected in the first second of the forced expiratory manoeuvre

Question 35

what diseases can reduce peak flow and spirometry measurements

Answer 35

asthma & COPD (also emphysema & bronchitis)

Question 36

what diseases can a low FEV suggest?

Answer 36

restrictive ventilatory defects such as pulmonary fibrosis, asbestosis, pulmonary oedema and muscular dystrophy

Question 37

what diseases can reduced FEV1 (with slightly reduced FVC) suggest?

Answer 37

obstructive ventilatory defects including asthma, COPD and bronchiectasis

Question 38

activation of what receptor causes bronchoconstriction

Answer 38

occurs due to the action of Acetylcholine on Muscarinic (M2 & M3) receptors on the bronchial smooth muscle

Question 39

activation of what receptor causes bronchodilation

Answer 39

β2-adrenergic control

Question 40

what drugs should be avoided in asthma

Answer 40

beta blockers and NSAIDS

Question 41

what disease does low FEV1 and FVC suggest?

Answer 41

restrictive ventilatory defects eg pulmonary fibrosis (also reduced TLC)