Respiratory embryology Flashcards
What is laryngotracheal groove and when does it start developing?
It is median tubular outgrowth from ventral wall of foregut -diverticulum that will develop into trachea and lung buds. It starts developing at week 4
What happens to proliferating bud?
Proliferating bud invaginate both pleural cavities laterally forming visceral and parietal pleura
How does trachea and oesophagus separate?
By tracheoespphageal septum that separates trachea and oesophagus ventrally and dorsally, trachea is anterior and oesophagus is posterior
What is treacheoesophageal fistula?
Passage between the two
What is oesophageal atresia?
Blind ended oesophagus, oesophagus ends and does not connect to loweroesophagus and stomach
What is transverse septal shelf?
Shelf that develops between the thorax and abdomen, separates two cavities
What are the 4 components of the diaphragm?
septum transversum, pleuroperitoneal membranes, peripheral body wall muscle, mesentery of oesophagus
What forms from septum transversum ?
tedious part of diaphragm, initially located opposite C3 to C5 somites, migrates caudally and takes all its innervation with it
What forms form 2 pleuroperitoneal membranes ?
muscular part of diaphragm
What is formed from peripheral body wall muscle ?
Muscular part, peripheral parts of the diaphragm, those that are innervated by intercostal nerves
What is formed from mesentery of oesophagus ?
Crura of diaphragm
Name the stages in the differentiation of the lung bud
Embryonic, pseudoglandular, canalicular, saccular and alveolar
What happens during the embryonic development ?
respiratory diverticulum appear around day 26 from the ventral part of foregut, it then develops to trace and two lateral pockets, simultaneously vascular connections develop, pulmonary arteries
What happends during foetal period?
pseudoglandular, canalicular, saccular stage
What happens in speudoglandular stage?
pulmonary structures are set up except elements needed for gas exchange, initial proliferation into glands
What happens in canalicular stage?
terminal bronchioles give rise to tubules that makes the respiratory portion, differentiation of epithelium into cuboidal security cells type II pneumocytes and flat cells type I pneumocytes
What happens during saccular stage?
Formation of alveolar sacks by primary septum progressive divided into smaller units
What happens in alveolar stage?
This is post natal stage, formation of alveoli form terminal sacs, they enlarge, by the age of 8 years the number of alveoli reaches adult number
What are the possible congenital malformations of respiratory system?
Respiratory distress syndrome, accessory lobes, agenesis of lungs, lobe of azygous vien, pulmonary hypoplasia, hiatal hernias, diaphragmatic hernias
