Respiratory Development and Disorders

Question 1

What are the five stages in lung development?

Answer 1

embryonic stage
pseudo-glandular stage
canalicular stage
saccular stage
alveolar stage

Question 2

which lung development stages continue after birth?

Answer 2

later end of saccular stage

alveolar stage

Question 3

what happens during the embryonic stage of lung development?

Answer 3

lung bud rises out of the gut tube

Question 4

what happens during the pseudo-glandular stage of lung development?

Answer 4

main bronchi and bronchioles are formed, but no contact with blood vessels

Question 5

what happens during the canalicular stage of lung development?

Answer 5

blood vessels grow closer to formed airways

gas/blood barrier is formed for gas exchange

Question 6

what happens during the saccular and alveolar stages of lung development?

Answer 6

alveoli and alveolar sacs undergo septation and multiply in the lung

Question 7

which stages are termed pre-acinar and which ones post-acinar?

Answer 7

pre-acinar: embryonic and pseudo-glandular

post-acinar: canalicular, saccular and alveolar

Question 8

which developmental lung disorders are more likely to occur in the pre-acinar stage?

Answer 8

airway stenosis
tracheobronchomalacia
pulmonary agenesis/hypoplasia
tracheo-oesophageal fistula

Question 9

what developmental lung disorders are more likely to occur in the post-acinar stage?

Answer 9

bronchogenic cyst
cystic adenomatoid malformation
pulmonary sequestration
lobar emphysema

Question 10

how is a developmental lung disorder likely to present in a fetus, a newborn and a child?

Answer 10

fetus - picked up in fetal ultrasound scan
newborn - tachypnea, respiratory distress
child - stridor/wheeze, incidental finding, recurrent RTIs

Question 11

what are the possible symptoms of tracheobronchomalacia?

Answer 11

breathless on exertion
wheeze/stridor
recurrent croup
barking cough

Question 12

what is the best management for tracheobronchomalacia?

Answer 12

antibiotics when needed

respiratory physiotherapy

Question 13

what should never be given to children with tracheobronchomalacia?

Answer 13

beta agonists

Question 14

what is a possible risk associated with cystic adenomatoid malformations?

Answer 14

there is a risk they will become malignant

Question 15

what is the best management of cystic adenomatoid malformations, and why?

Answer 15

conservative management, because it is best resolved on its own

Question 16

what are two possible developmental lung disorders associated with diaphragm malformations?

Answer 16

diaphragmatic hernia

diaphragmatic eventration

Question 17

which diaphragmatic developmental abnormality is often found incidentally?

Answer 17

diaphragmatic eventration

Question 18

which diaphragmatic developmental abnormality can cause lung hypoplasia, hypertension and structural abnormalities?

Answer 18

diaphragmatic hernia

Question 19

what is a possible cause for infant respiratory distress syndrome?

Answer 19

hyaline membran disease

Question 20

what is the pathophysiology underlying hyaline membrane disease?

Answer 20

the lack of endogenous surfactant at birth

Question 21

what is the best management of hyaline membrane disease in babies?

Answer 21

glucocorticoids
surfactant replacement
mechanical ventilation

Question 22

what is chronic neonatal lung disease caused by, and what disease does is mimic?

Answer 22

multifactorial: O2 toxicity/infection/genetics/PDA

looks similar to COPD

Question 23

what disease do symptoms of chronic neonatal lung disease mimic?

Answer 23

COPD

Question 24

what can be some factors affecting development, which may lead to COPD in later life?

Answer 24

fetal/neonatal infections
nutrition (maternal/neonatal)
nicotine exposure 
alpha 1 AT deficiency
environmental pollution

Question 25

what is meant by lung spare capacity?

Answer 25

the ability of the lung to function as normal (asymptomatic) if there is a decline in lung function

Question 26

what is meant by the term tissue remodelling?

Answer 26

it’s the altered structure of a tissue because of external factors

Question 27

what are some examples of lung remodelling due to factors occurring in early lung development stages?

Answer 27

asthma

chronic neonatal lung disease

Question 28

what is a major factor affecting lung remodelling?

Answer 28

nicotine exposure

Question 29

what are some of the outcomes of nicotine exposure at an early age, in terms of lung development?

Answer 29

lung hypoplasia
reduced alveolarisation
impaired cell-cell signalling
reduced lung function

Question 30

what is the fletcher-peto curve?

Answer 30

it’s a hypothesis which shows how smoking affects lung function at earlier stages in people’s lives

Question 31

what disease is more likely to occur in people who had lung remodelling as children, due to environmental factors (eg smoking)?

Answer 31

COPD