Developmental Lung Disease Flashcards
What are the stages of lung morphogenesis?
- Embryonic
- Pseudo-Glandular
- Canicular
- Saccular
- Alveolar
What forms in the embryonic stage?
A laryngo-tracheal groove on the oesophagus which eventullay seperates into the trachea.
What forms during the pseudo-glandular phase?
Bronchi form and seperate into the lobes that will eventually make up the lung.
Myofibroblasts and tubules form,
gas exchange isnt possible yet though.
What occurs in the canalicular phase?
- Lot of cuboidal epithelium differentiates to squamous
- the blood vessel start to line the epithelium forming a blood-air barrier
What kind of lung development occurs postnatal?
Further alveolar septation (formation essentially).
100-150mill at birth to 200-600mill at 3-8 years.
At what stage of lung morphogenesis is surfactant produced?
IT becomes detectable in the saccular phase and is produced there and in the alveolar phase.
What kind of things can go wrong in embryonic phase?
Tracheal Stenosis - Constriction/narrowing of the trachea either short or long segment.
Tracheo-oesophageal fistula - joining of the 2 tubes.
Pulmonary Agenesis - The lung bud doesnt form.
What problems can occur in pseuoglandular phase?
- Cysts can form
- Pulmondary sequestration where part of the lung tissue is non-functioning and unconnected to the broncheal tree
- Cystadenomatoid malformation?
At what point does the diaphragm close?
Around 18 weeks
.On which side is a diaphragmatic hernia most likely?
Left
.What can a hernia of the diaphragm cause?
Pulmonary hypoplasia - Essentially when thers an abnormally low number or size of bronchopulmonary segments.
Persistant pulmonary hypertension
.What is eventration?
When the diaphragm muscle doesnt form properly and becomes weak eventually forming an unusual bulge and not contracting on inspiration. It often protudes upwards into the thorax
.What functional changes occur in the lungs at birth?
From fluid secretion to absorption
Pulmonary vasodilation
.What embryonic tissues contribute to the diaphragm?
Lots, a variety really
.What embryonic tissue contributes to the airways?
The endoderm produces the epithelial cells of the trachea, pharynx and the alveolar cells.
This protudes into the mesoderm too