Development of Trachea and Bronchi
- Laryngotracheal (respiratory) diverticulum forms during week 4 in floor of pharynx.
- Tracheoesophageal septum separates developing larynx and trachea from pharynx and esophagus
Esophageal atresia results in polyhydramnios.
- Lung buds develop in week 5 at caudal end of laryngotracheal tube, growing into splanchnic mesoderm surrounding foregut to give rise to primary, secondary, and tertiary bronchi by week 6
A congenital tracheoesophageal fistula is an abnormal communication between the trachea and distal esophagus usually associated with esophageal atresia (blind-ending esophagus) . The resulting regurgitation and aspiration of swallowed milk (and possible reflux of gastric contents into lungs) cause pneumonia. Because esophageal atresia prevents the fetus from swallowing and absorbing amniotic fluid in the small intestine, the condition is often accompanied by excess amniotic fluid (polyhydramnios). An acquired tracheoesophageal fistula may result from malignancy, infection, or trauma.
Tracheoesophageal fistula with esophageal atresia causes pneumonia.