File:Stage7 cloacal-oral-membranes.jpg: Difference between revisions

Revision as of 16:01, 17 August 2014

Carnegie Stages 7 showing approximate regions where buccopharyngeal and cloacal membranes would lie on the embryonic disc.

Features: embryonic disc, primitive node, primative streak, primative groove, yolk sac

Facts: Week 3, 15 - 17 days, 0.4 mm

View 1: embryonic disc, showing the epiblast viewed from the amniotic (dorsal) side.

Stage 7 Labelled | Stage 7 Molecular | Stage 7 SEM | Stage 8

Events: Gastrulation is continuing as cells migrate from the epiblast, continuing to form mesoderm.

Mesoderm lies between the ectoderm and endoderm as a continuous sheet except at the buccopharyngeal and cloacal membranes. These membranes have ectoderm and endoderm only and will lie at the rostral (head) and caudal (tail) of the gastrointestinal tract.

From the primitive node a tube extends under the ectoderm in the opposite direction to the primitive streak. This tube forms first the axial process then notochordal process, then finally the notochord.

The notochord is a key to embryonic folding and regulation of ectoderm and mesoderm differentiation. It lies in the rostrocordal axis and the embryonic disc will fold either side ventrally, pinching off a portion of the yolk sac to form the lining of the gastrointestinal tract.

Blue dot (top) - buccopharyngeal membrane
Blue dot (middle) - primitive node
Blue dot (bottom) - cloacal membrane
grey line - primitive streak

Stage 7 Links: :Carnegie stage 7 | Gastrulation | Mesoderm

Embryo Stage 7 (dorsal)
Dorsal view
Primitive streak and node
Oral and cloacal membranes
Axial mesoderm
Paraxial mesoderm
Intermediate mesoderm
Lateral plate

Reference

Image Source: UNSW Embryology

No image reuse without permission.

File history

Yi efo/eka'e gwa ebo wo le nyangagi wuncin ye kamina wunga tinya nan

	Gwalagizhi	Nyangagi	Dimensions	User	Comment
current	11:15, 10 August 2009		690 × 800 (70 KB)	MarkHill (talk \| contribs)	Carnegie Stages 7 showing approximate regions where buccopharyngeal and cloacal membranes would lie on the embryonic disc. Features: embryonic disc, primitive node, primative streak, primative groove, yolk sac Facts: Week 3, 15 - 17 days, 0.4 mm View 1

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@@ Line 1: / Line 1: @@
 Carnegie Stages 7 showing approximate regions where buccopharyngeal and cloacal membranes would lie on the embryonic disc.
+{|
-Features: embryonic disc, primitive node, primative streak, primative groove, yolk sac
+| Features: embryonic disc, primitive node, primative streak, primative groove, yolk sac
 Facts: Week 3, 15 - 17 days, 0.4 mm
@@ Line 16: / Line 16: @@
 The notochord is a key to embryonic folding and regulation of ectoderm and mesoderm differentiation. It lies in the rostrocordal axis and the embryonic disc will fold either side ventrally, pinching off a portion of the yolk sac to form the lining of the gastrointestinal tract.
+| valign=top width=200px|
+* Blue dot (top) -  buccopharyngeal membrane
+* Blue dot (middle) - primitive node
+* Blue dot (bottom) -  cloacal membrane
+* grey line - primitive streak
-Image Source: UNSW Embryology http://embryology.med.unsw.edu.au/wwwhuman/Stages/stage7.htm
+:[[Carnegie stage 7|Stage 7 Links]]: :[[Carnegie stage 7]] | [[Gastrulation]] | [[Mesoderm]]
+|}
+{{Stage 7 mesoderm images}}
+===Reference===
+Image Source: UNSW Embryology
 No image reuse without permission.
-[[Category:Week 3]]