- Blood island
Infobox Embryology
Name = PAGENAME
Latin =
GraySubject = 135
GrayPage = 506
Caption =
Caption2 =
Days = 21
CarnegieStage = 6a
Precursor =mesoderm
System =
MeshName =
MeshNumber =
DorlandsPre = i_13
DorlandsSuf = 12460968Blood islands are structures in the developing
embryo which lead to many different parts of the circulatory system.They primarily derive from
plexuses formed fromangioblasts . Within them,vacuoles appear throughliquefaction of the central part of thesyncytium into plasma. The lumen of theblood vessels thus formed is probably intracellular. The flattened cells at the periphery form theendothelium .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 thedorsal aorta .External links
*
* [http://www.brown.edu/Courses/BI0032/stemcell/vascu.htm "Development of the vascular system"] at brown.edu
* http://embryology.med.unsw.edu.au/Notes/heart20.htm
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