File:Stage8 sem3.jpg

From Embryology

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Scanning EM showing detail of the Nodal Cilia

Human embryo (Stage 8, day 18) nodal cilia are the long cellular processes, the shorter processes visible on cells in the image are microvilli.

Nodal cilia (microtubule-based motile cell structures) are thought to act to "stir" the overlying fluid layer at the time of gastrulation. This fluid contains secreted morphogens that are moved in one direction and therefore may have a role in establishing the initial embryo left/right axis.


Microvilli (microfilament-based non-motile cell structures) increase the cell membrane surface area for absorption and secretion.


Links: Stage 8 | Gastrulation | Nodal Cilia Movie | Cilium cartoon

Image Source: Scanning electron micrographs of the Carnegie stages of the early human embryos are reproduced with the permission of Prof Kathy Sulik, from embryos collected by Dr. Vekemans and Tania Attié-Bitach. Images are for educational purposes only and cannot be reproduced electronically or in writing without permission.

Embryonic Development

Original file name:Stage8day18nodalcilia.jpg

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current08:59, 22 August 2009Thumbnail for version as of 08:59, 22 August 20091,000 × 709 (91 KB)S8600021 (talk | contribs)Human embryo (Stage 8, day 18) Scanning EM showing detail of the nodal cilia. Original file name:Stage8day18nodalcilia.jpg {{Template:SEM}}