[LE 03] Endoderm Flashcards
roles of the endoderm
- instruct formation of the notochord, heart, blood vessels, and mesodermal germ layer
- construct digestive and respiratory tubes
- form the epithelium of tonsils, thyroid gland, thymus, and parathyroid gland
t or f: endoderm construct the digestive and respiratory tubes
t
t or f: mesodermal layer has instructions for endoderm development
t
t or f: before the digestive tube becomes a tube, it must undergo embryonic folding
t
embryonic folding in the horizontal plane results to what structures?
lateral body folds
embryonic folding in the median plane results to what structures?
cranial and caudal folds
t or f: the endoderm is responsible for the formation of the gastrointestinal tract
t
primitive gut tube differentiates into these parts
- foregut
- midgut
- hindgut
the foregut is temporarily closed by what structure?
oropharyngeal membrane
the oropharyngeal membrane ruptures to form what srtucture?
mouth
stalk connection to the yolk sac formed during embryonic folding
vitelline duct
hindgut is temporarily closed by what structure?
cloacal membrane
cloacal membrane ruptures to form what structure?
cloacal and anal openings
t or f: the foregut only gives rise to the pharynx and lungs
f; also gives rise to the cranial parts of the digestive canal:
- esophagus
- stomach
- duodenum
- liver
- gall bladder
- pancreas
the midgut gives rise to what structures?
middle parts of the digestive canal:
- duodenum
- jejunum
- caecum
- ascending colon
- transversing colon
the hindgut gives rise to what structures?
- allantois
- urogenital sinus
- transversing colon
- descending colon
- rectum
t or f: endodermal cells will develop into progenitor cells of the
lungs even without Bmp
f; needs even a small amount of BMP (it is a gradient)
gradient of signals needed in the endoderm and gut tube patterning
BMPs, FGFs, Wnts
Loss of Nodal will result to failure in endoderm specification
t
signal present for endoderm specification
nodal
signals present for mesoderm specification
BMP and FGF
this signal is expressed if endoderm is differentiated
Sox17
AFG becomes?
lung and thyroid
PFG becomes?
hepatoblast and pancreas
MG-HG becomes?
intestine
most posterior signals in endoderm and gut tube patterning
BMPs, FGFs, Wnts
what structures create the pharyngeal arches?
pharyngeal grooves