THE DEVELOPMENT OF BLOOD CAPILLARIES IN HUMAN FETAL BRAIN——AN ULTRASTRUCTURAL AND QUANTITATIVE STUDY / 解剖学报

ABSTRACT

It is generally accepted that the permeability of the blood-brain barrier in the fetus is higher than in the adult, but its structural basis is still not well known. In this paper, an ultrastructural study was performed on the cerebral capillaries of human fetus aged from 5-9 months and some structural parameters were measured. The results were as follows (1) the endothelial tight junctions were longer and tortuous, and the clefts within the junctions were found and did not show apparent change in all groups; (2) the plasmalemmal vesicles were larger in 5th month than in the 9th month, and the density of vesicles was low (