Cite

Copy

Tap on and choose 'Add to Home Screen' to create a shortcut app

Tap on and choose 'Add to Home Screen/Install App' to create a shortcut app

Blastogenesis

This page was last updated on July 15th, 2017

Blastogenesis is the initial phase of differentiation that results in formation of the prochordal plate (1, 2, 3).

Cell Division

During POD 1–4 the human embryo undergoes approximately five rounds of cell division to produce 32-cell morula.

  • Inner cell mass: The inner cell mass gives rise to the embryo proper.
  • Trophoblastic cells: The surrounding trophoblast cells give rise to placental tissues.

Differentiation of Inner Cell Mass

The inner cell mass differentiates into two layers:

  • Epiblast: The dorsal layer of the inner cell mass.
  • Hypoblast: The ventral cell layer of the inner cell mass.

Formation of Amnionic and Yolk Cell Cavities

  • Amnionic sac: This cavity develops dorsal to the inner cell mass by POD 12.
  • Yolk sac: This cavity develops ventral to the inner cell mass by POD 12.

Formation of Prochordal Plate

  • Formation of cranial end: The cranial end of the embryo is visible by POD 13 as the prochordal plate, a thickening of the cranial end of the embryo, becomes visible.

 

Early formation of the embryo: A. Formation of inner cell mass and surrounding trophoblast. B. Formation of epiblast, hypoblast, and amnionic sac. C. Formation of prochordal plate (craniocaudal orientation). From Dias and McLone (2).

 

Your donations keep us going

The ISPN Guide is free to use, but we rely on donations to fund our ongoing work and to maintain more than a thousand pages of information created to disseminate the most up-to-date knowledge in the field of paediatric neurosurgery.

By making a donation to The ISPN Guide you are also indirectly helping the many thousands of children around the world whose treatment depends on well-informed surgeons.

Please consider making a donation today.

Use the app

The ISPN Guide can be used as a standalone app, both on mobile devices and desktop computers. It’s quick and easy to use.

Fully featured

Free registration grants you full access to The Guide and host of featured designed to help further your own education.

Stay updated

The ISPN Guide continues to expand both in breadth and depth. Join our mailing list to stay up-to-date with our progress.