Embryology (respiratory) Flashcards
Where do the lungs and trachea develop from?
The primitive gut tube which forms from the endoderm
When do the trachea and lung buds start to form?
Week 4
They bud out from the anterior wall of the primitive foregut
What is an atresia?
A condition in which a passage in the body is closed or absent.
What is a fistula?
Am abnormal passage between 2 tubes or surfaces
What does the pleura develop from?
Lateral plate mesoderm
The splanchnic layer forms the visceral pleura and the somatic layer forms the parietal pleura
What seals off the pleural cavities from the pericardial cavity?
Pleuropericardial folds
What is the pseudoglandular stage of lung development?
7-17 weeks
Development of lung except respiratory part
What is the canalicular stage?
17-27 weeks
Formation of alveolar ducts and epithelium starts to differentiate into type 1 and type 2 pneumocytes (no gas exchange)
What is the saccular stage?
27-40 weeks
Formation of alveolar sacs, primitive alveoli and surfactant (gas exchange)
What is the alveolar stage?
32 weeks to 8 years
Proliferation of alveoli from alveolar sacs
What does the central tendon of the diaphragm form from?
Septum transversum
What do the pleuroperitoneal folds do?
They close off the pleuroperitoneal canals, separating the pleural cavities from the peritoneal cavity. These folds carry the lower intercostal nerves to supply the periphery of the diagram.
What forms the muscular part of the diaphragm?
Skeletal muscle in growth from the peripheral body wall. From somites C3-C5 these carry the phrenic nerve to the muscular part
What forms the diaphragmatic crura?
The dorsal mésentère of the oesophagus
What weak area can cause a hiatus hernia?
Oesophageal hiatus
