Studies of a single placental cotyledon in vitro: III. The dimensions of the villous capillaries.
The capillary beds of ten isolated perfused placental cotyledons were examined by injecting microspheres ranging from 2 microgram to more than 20 microgram diameter into the villous circulation. As many as 25 per cent of capillaries may be less than 4 microgram in diameter; there are virtually none whose diameter exceeds 11 microgram and there is no evidence of large diameter vascular shunts.
D002196:Capillaries / Q000033:anatomy & histology*; D003037:Cobalt Radioisotopes; D005260:Female; D006801:Humans; D008722:Methods; D008863:Microspheres; D010920:Placenta / Q000098:blood supply*; D011247:Pregnancy
D003037:Cobalt Radioisotopes