epithelia from lung rudiments in which secondary bronchial buds are already established ( 14th and 13th gestational day for rat and mouse respectively ) are able to undergo branching morphogenesis and cytodifferentiation in submandibular mesenchyme in vitro , whereas lung epithelium from one day younger foetuses rarely gives a morphogenetic response to submandibular mesenchyme and usually differentiates into primary ( non-budding ) bronchial epithelium .
C0265783
lung rudiments
C0024109
lung