Neonatal and Pediatric Pulmonary disease Flashcards
When can lung lobes be distinguished?
week 12. branching complete at week 16
What is the most important development during the canalicular phase?
formation of alveolar duct and air sacs (lined with cuboidal cells)
When is the alveolar stage?
aka viable stage. begins 26-28 weeks
What agents accelerate surfactant maturation?
cortisone, stress, thyroxine, prolactin, theophylline, sympathomimetics
what agents decrease rate of surfactant maturation?
insulin, metapyrone (steroid antag), barbituates
What aspects of lung development occur in the 3rd trimester?
increase in surfactant and development of respiratory control
How does a vaginal birth assist in lung development?
expels amniotic fluid from the lungs (squeezes the thorax- chest wall spring effect), creates negative intrathoracic pressure for first breath of air.
Until when does alveolar proliferation occur?
8-10 years
What changes in the lungs between ages 10 and 20?
SIZE of alveoli (rather than proliferation)
When would an insult occur leading to tracheoesophageal fistula?
4th week
what is the etiology of tracheo-esophogeal fistula?
failure of separation of esophageal and lung buds from the foregut
When would an insult occur that leads to an absence of lung or lobe?
4-8 weeks
what would cause absence of a lung or lung bud?
failure of airway budding into mesenchyme
when would an insult in pregnancy lead to cyst development?
weeks 4 to 12
What causes a cyst formation?
abnormal detachment of lung tissue from primitive airway buds… connect to bronchial tree by defective airway
