B4.034 Prework Embryology Flashcards
what parts of the respiration system arise from the endoderm?
epithelium of the trachea, primary bronchi, bronchial tree, bronchioles and alveoli
what parts of the respiration system arise from the splanchnic mesoderm?
other strata of the trachea, primary bronchi, bronchial tree, bronchioles and alveoli
also blood and lymphatic vessels
what determines how lung epithelium differentiates?
source of the mesenchyme it is exposed to
pericardioperitoneal canals
openings into which lung buds grow
become pleural space
pleuropericardial fold
separates pleural cavity from pericardium
pleuroperitoneal folds
separate pleural space from peritoneum
become a part of the diaphragm
major components of the diaphragm
pleuroperitoneal membrane
septum transversum
body wall (mesoderm)
what is a diaphragmatic hernia?
congenital absence of large area of diaphragm through which the guts move into the pleural cavity
what are FGF and TGFB
growth factors
fibroblast growth factor
transforming growth factor
mesenchymal signals
what is Shh
sonic hedgehog
morphogen involved in epithelial signaling
major players in lunch branching morphogenesis
FGF10
Shh
BMP4
what is the importance of FGF10
best candidate “branching signal” in the mesenchyme
expressed in patches in the mesenchyme adjacent to a future branch point and stimulates chemotaxis and proliferation in the epithelium
describe the process of branching
FGF10 (mesenchymal) interacts with FGF-R (epithelial) and induces bud formation and extension
FGF induces BMP4 and Sprouty in branch tip
BMP4 inhibits epithelial cell division limiting branch extension
Shh inhibits FGF in mesenchyme around branch tip, splitting the FGF expression and promoting next round of branching
Sprouty restricts branching to the tip, TGFB stimulates ECM deposition and inhibits cell proliferation