Blood vessels first make their appearance in several scattered vascular areas that are developed simultaneously between the endoderm and the mesoderm of the yolk-sac, i. e., outside the body of the embryo. Here a new type of cell, the angioblast or vasoformative cell, is differentiated from the mesoderm.

These cells as they divide form small, dense syncytial masses, which soon join with similar masses by means of fine processes to form plexuses.

Angioblasts are one of the two products formed from hemangioblasts (the other being pluripotential hemopoietic stem cells).

[edit] External links

• Gray's page #505
• Diagram at uiowa.edu
• "Development of the vascular system", at brown.edu
• Alternative Sources Of Angioblasts

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.