Pulmonary System Embryology 1 Flashcards
What germ layer forms the epithelial lining of the respiratory tract?
Endoderm
What is the sulcus larngotrachealis?
A groove in the ventral lower pharynx that will develop into the lungs
What is the next step in lung development?
The true lung primordium buds from the lower portion
After the true lung primordium forms, what happens next?
it divides into 2 main bronchi and the endodermal branches into the lobes
When can the lung primordium first be observed?
Twenty-eight days
What epiglottis develops from what structure?
They hypopharyngeal eminence
What cell is the precursor of ciliated epithelium and secretory cells in the pulmonary system?
Cubic epithelium
A premature fetus born after 26 weeks has better survival odds thanks to what?
Capillaries have bulged into developing alveoli thus establishing a blood-air barrier and allowing for adequate gas exchange
At what point of development are the terminal saccules lined with type 1 alveolar cells?
By week 26
When do type II alveolar cells start producing surfactant?
By week 20 small amounts are produced, but adequate levels for survival are only produced around week 26 to 28
