Hypoblast
Encyclopedia
The hypoblast is a tissue type that forms from the inner cell mass
. It lies beneath the epiblast
and consists of small cuboidal cells.
Extraembryonic endoderm (including Yolk sac
) is derived from hypoblast.
Inner cell mass
In early embryogenesis of most eutherian mammals, the inner cell mass is the mass of cells inside the primordial embryo that will eventually give rise to the definitive structures of the fetus...
. It lies beneath the epiblast
Epiblast
In amniote animal embryology, the epiblast is a tissue type derived either from the inner cell mass in mammals or the blastodisc in birds and reptiles. It lies above the hypoblast.-Mammals:...
and consists of small cuboidal cells.
Extraembryonic endoderm (including Yolk sac
Yolk sac
The yolk sac is a membranous sac attached to an embryo, providing early nourishment in the form of yolk in bony fishes, sharks, reptiles, birds, and primitive mammals...
) is derived from hypoblast.
External links
- http://www.embryology.ch/allemand/iperiodembry/carnegie02.html
- http://www.med.umich.edu/lrc/coursepages/M1/embryology/embryo/04secondweek.htm
- http://isc.temple.edu/marino/embryology/EMBII97/sld005.htm