Angiogenesis

Angiogenesis

10.170.10^Angiogenesis|10.320.30.10^Angiogenesis|60.400.30.10^Angiogenesis

Angiogenesis is a physiological process involving the growth of new blood vessels from preexisting vessels. Placental vascular growth begins as early as 21 days p.c. and continues throughout gestation. When the primary villi are formed, the cytotrophoblast core is covered by a thick layer of syncytiotrophoblasts. With the development of secondary villi, a core of irregularly dispersed, homogenous connective tissue cells can be recognized beneath the cytotrophoblast layer. At 6 weeks of gestation, a basal lamina can be detected around the villous vessels. The development of villous capillaries from hemangioblastic cells can be observed until 10–12 weeks of gestation. From 12 weeks onwards, the capillaries coil, bulge, form sinusoids, and protrude towards the trophoblastic layers, forming a so-called syncytiocapillary membrane. Although reliable signs of formation of new vessels are absent in the second half of pregnancy, some capillary sprouts can be seen. Wang Y, Zhao S. Vascular Biology of the Placenta. San Rafael (CA): Morgan & Claypool Life Sciences; 2010. Chapter 6, Vasculogenesis and Angiogenesis of Human Placenta. Available from: http://www.ncbi.nlm.nih.gov/books/NBK53252/ 2014/10/10 (RD)

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