lung development Flashcards
lung growth and development continuum: recognise the continuum of lung growth and development from conception to adulthood, explain the factors that interfere with normal development, and recall the early life origins of susceptibility to lung disease
embryonic phase: 0-7 weeks
lobar airways (lung buds, main bronchi)
pseudoglandular: 5-17 weeks
pre-acinar airways complete (conducting airways, bronchi and bronchioli)
canalicular: 16-27 weeks
respiratory airways, blood gas barrier
saccular/alveolar: 28-40 weeks
alveoli appear, multiplying and enlarging in size with chest cavity
early foetal life
majority of complex airway and circulatory system grown; 1/3-1/2 adult alveolar present at birth, and most by 3 y/o
inhibitory growth factors
TGFB affecting matrix synthesis; retinoic acic inhibiting branching
lung growth abnormalities: angenesis, aplasia, hypoplasia, lack of growth
agenesis (rare; complete absence of lung and vessel); aplasia (blind ending bronchus, no lung or vessel); hypoplasia (bronchus and rudimentary lungs present, but reduced in size or number due to lack of space caused by intra/extrathoracic such as hernia, cardiac mass), lack of growth (CTM)
