Warning: The NCBI web site requires JavaScript to function. more...
An official website of the United States government
The .gov means it's official. Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you're on a federal government site.
The site is secure. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.
The outer of the three germ layers of an embryo.
PubMed search builder options
Subheadings:
Restrict to MeSH Major Topic.
Do not include MeSH terms found below this term in the MeSH hierarchy.
Tree Number(s): A16.504.273
MeSH Unique ID: D004475
Entry Terms: