Blood island
From Wikipedia, the free encyclopedia
| Blood island | ||
|---|---|---|
| Gray's | subject #135 506 | |
| Carnegie stage | 6a | |
| Days | 21 | |
| Precursor | mesoderm | |
| Dorlands/Elsevier | i_13/12460968 | |
Blood islands are structures in the developing embryo which lead to many different parts of the circulatory system.
They primarily derive from plexuses formed from angioblasts. Within them, vacuoles appear through liquefaction of the central part of the syncytium into plasma.
The lumen of the blood vessels thus formed is probably intracellular.
The flattened cells at the periphery form the endothelium.
The nucleated red blood corpuscles develop either from small masses of the original angioblast left attached to the inner wall of the lumen or directly from the flat endothelial cells.
In either case the syncytial mass thus formed projects from and is attached to the wall of the vessel.
Such a mass is known as a blood island and hemoglobin gradually accumulates within it.
Later the cells on the surface round up, giving the mass a mulberry-like appearance.
Then the red blood cells break loose and are carried away in the plasma.
Such free blood cells continue to divide.
Blood islands have been seen in the area vasculosa in the omphalomesenteric vein and arteries, and in the dorsal aorta.
[edit] External links
- Embryology at Temple Heart98/heart97a/sld008
- "Development of the vascular system" at brown.edu
- http://embryology.med.unsw.edu.au/Notes/heart20.htm
|
||||||||
 |
This cardiovascular system article is a stub. You can help Wikipedia by expanding it. |
 |
This developmental biology article is a stub. You can help Wikipedia by expanding it. |
This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.
