Embryonic disc

  (Redirected from Embryonic disk)

The embryonic disc (or embryonic disk) forms the floor of the amniotic cavity. It is composed of a layer of prismatic cells – the embryonic ectoderm, derived from the inner cell mass and lying in apposition with the endoderm.

Embryonic disc
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Section through embryonic disc of a parti-coloured bat.
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Surface view of embryo of a rabbit. (After Kölliker.) arg. Embryonic disc. pr. Primitive streak.
Details
Carnegie stage4
PrecursorEctoderm
Identifiers
Latindiscus embryonicus
TEE2.0.1.2.0.0.14
Anatomical terminology

In humans, it is the stage of development that occurs after implantation and prior to the embryonic folding (e.g. seen between about day 14 to day 21 post fertilization). It is derived from the epiblast layer, which lies between the hypoblast layer and the amnion. The epiblast layer is derived from the inner cell mass. Through the process of gastrulation, the bilaminar embryonic disc becomes trilaminar. The notochord forms thereafter. Through the process of neurulation, the notochord induces the formation of the neural tube in the embryonic disc.

ReferencesEdit

This article incorporates text in the public domain from page 47 of the 20th edition of Gray's Anatomy (1918)

External linksEdit