The fetal microcirculation of the term human placenta offers an interesting microvascular
model. A perfused placenta can be used for integrated studies of vascular permeability-
structure relationships. The organization of the paracellular pathway in human placental
microvessels closely resembles not only that of the guinea-pig placenta, but also that seen
in typical continuous non-cerebral capillaries such as those of the myocardium. This
uniformity of organization has allowed the development of a model of the organization of …