Development of cardio/pulm Flashcards
In what direction does the laryngeotracheal diverticulum grow?
distally, and is separated from the esophagus by the tracheoesophageal septum
What is tracheoesophageal fistula?
- most common abnormality
2. improper formation of the tracheoesophageal septum
What is an esophageal atresia, and can this accompany a tracheoesophageal fistula?
- failure of the esophagus to properly form with the stomach.
- yes
What would be associated with EA, and TEF?
polyhydramnios, baby will not be able to swallow, and if so it will not be able to pas to the stomach
When do the trachea divide into the 2 bronchial buds?
week 4, which will become the primary bronchi
When do secondary bronchial buds form?
week 5 followed by the tertiary at week 6
What tissue differentiates into the smooth muscle, nerves, and blood vessels of the lungs?
splanchnic mesoderm
What are the stages and time periods of lung development?
- embryonic (4-7wk)
- pseudoglandular (8-16wk)
- CANALICULAR (17-26wk)
- terminal sac (26wk to birth)
- postnatal (alveolar)
What forms during the embryonic stage of development at weeks 4-7?
- respiratory diverticulum and major bronchopulmonary segments
- lung grow into pleural cavity
- pleura differentiates
What forms during the pseudo glandular stage, 8-16wks?
- duct system of bronchopulmonary segment
2. no respiratory components
What forms during canalicular stage, 17-26wks?
- respiratory bronchioles and terminal sacs
- increased vascularization
- capillaries develop in walls
- earliest possibly survivable birth
What happens during the terminal sacular stage? 26wk to birth?
- alveoli develop from respiratory bronchioles
2. epithelial lining differentiates into two cell types
What are the type I and type II pneumocytes used for in the lungs?
- type I: form air-blood barrier
2. type II: secrete surfactant, aids in alveolar expansion
What occurs in the postnatal stage of development?
- 90% alveoli form via septation of pre-existing alveoli
What can lead to infant respiratory distress syndrome, via immature or damaged type II pneumocytes?
- premature
How can low surfactant levels lead to IRDS?
causes lung collapse which causes hypoxia and sometimes death