A study of the ultrastructure of developing human umbilical vessels.
Electron microscopic techniques were used to examine the ultrastructure of developing human umbilical arteries and vein (8-12, 13-17 and 37-40 wk gestational age). These showed that with increasing age there is (1) an increase in the size of the lumen and the thickness of the media; (2) an increase in the ratio of contractile smooth muscle phenotypic cells; (3) an increase in the myofilament content of the smooth muscle cells and the number of Weibel-Palade bodies; (4) a decrease in the glycogen content; (5) an appearance of microvilli on the luminal surface of the endothelium. Lipid vesicles, nerves and vasa vasorum were not observed in any region of the umbilical vein or arteries.
Sexton
A J
AJ
Department of Anatomy and Development Biology, University College London, UK.
Turmaine
M
M
Cai
W Q
WQ
Burnstock
G
G
D004730:Endothelium, Vascular / Q000648:ultrastructure; D005260:Female; D005865:Gestational Age; D006801:Humans; D008854:Microscopy, Electron; D009131:Muscle, Smooth, Vascular / Q000648:ultrastructure; D011247:Pregnancy; D014469:Umbilical Arteries / Q000254:growth & development* / Q000648:ultrastructure*; D014471:Umbilical Veins / Q000254:growth & development* / Q000648:ultrastructure*