What's the difference between ectoblast and entoblast?
Ectoblast
Definition:
(n.) The outer layer of the blastoderm; the epiblast; the ectoderm.
(n.) The outer envelope of a cell; the cell wall.
Example Sentences:
(1) Three main groups are described : ectoblastic, mesoblastic and entoblastic phacomatoses.
(2) Ectoblast cells were isolated and cultured with ECM taken from the embryonal regions.
(3) Ectoblastic cells explanted from the animal pole of young Xenopus laevis gastrulae have been cultured in vitro.
(4) The epiblastic cells treated with dorsal ECM, mainly located at the interphase between the invaginating blastoporal lip and the overlying ectoblast differentiated morphologically into neural, mesenchyme and pigment cells.
(5) The amount of cement gland in the ectoblastic explants varied according to the egg-batch and on the average accounted for 55 percent of the total tissue.
(6) Three monoclonal antibodies 5.1.H, 8.7.D and 13.7.A raised against semi-purified Tera 1 membrane fractions recognize distinct onco-foetal antigens which are developmentally regulated on cells such as Tera 2 clone 13 and appear to be restricted in their expression to undifferentiated ectoblastic cells and certain organized cystic structures mimicking the foetal intestine.
(7) Most of this undifferentiated tissue originates from the adjacent layer of the ectoblast.
(8) The facial complex and the brain develop separately from a common embryonic structure called ectoblast.
(9) This means that all or almost all of the competent superficial layer of the ectoblastic cells underwent differentiation into cement gland.
(10) The human skin and the mammary gland in the woman and the man--all of them ectoblastic-origin tissues, rich in stromal structures and belonging to the IIIrd step of Mârza's classification (Vth note) -- were investigated using the method of the microscopic conventional fields.
(11) Ectoblastic derivatives (ectodermal and neuroectodermal components) constitute more than 90% of all structures in the murine teratocarcinoma derived from the PCC4-aza-1 line.
(12) Although the treatment changed the fate of some ectoblastic tissues, it was unable to force endodermal or mesodermal tissues of the blastoporal lip to differentiate into cement gland.
(13) It is now postulated rather that, being derived at different periods of time from the embryonic epiblast--or perhaps, more accurately, ectoblast--they share a common neuroendocrine programme which is manifested by their possession of the acronymous amine-handling characteristics of the series and whose final expression is determined by microenvironmental circumstances.
Entoblast
Definition:
(n.) The inner germ layer; endoderm. See Nucleolus.
Example Sentences:
(1) In later stages, on human embryos of 11 to 16 mm (37 to 44 days of age; Carnegie stages 16 to 18), the mesoblastic anlage of the appendix is more evident, but it is not invaded by the entoblastic cells which come from the caecum on embryos of 12 to 13 mm.
(2) Three main groups are described : ectoblastic, mesoblastic and entoblastic phacomatoses.
(3) The diverses appearances of the tumor growths are expressed mainly in the range of cyto-differentiations of entoblastic tissue rather than in their ability to form structures which mimick the yolk-sac.
(4) On embryos of about 17 mm (48 days old; Carnegie stage 19) the entoblastic anlage of the appendix has invaded the original mesoblastic anlage.
(5) This infrequent malformation (9% of all childhood mediastinal tumors) is an entoblastic duplication of the digestive tract and is often accompanied with spinal malformations.
(6) The histogenesis of yolk-sac tumors has been explained by a selective cloning for extra-embryonic entoblast amongst totipotent carcinoma stemcells.
(7) The formation of the appendix by two anlage one earlier, mesoblastic, and another later, entoblastic, is similar to that of other lymphoid organs like the sack of Fabricius in birds.
(8) The tracheobronchial tree begins to form during the fourth week of development through a series of dichotomic divisions of an entoblastic evagination.