Vascularization of developing human olfactory neuroepithelium - a morphometric study.
The present study reveals intraepithelial capillaries in the olfactory neuroepithelium of human fetuses aged between 12 and 24 weeks of gestation, which disappear at birth. The area occupied by the intraepithelial capillaries increases significantly with fetal age (0.047 +/- 0.014 microm(2)/microm(2) at 12 weeks and 0.101 +/- 0. 025 microm(2)/microm(2) at 24 weeks) and with the thickness of the epithelium (45.00 +/- 6.74 microm at 8 weeks and 64.10 +/- 8.51 microm at 24 weeks). The vascularization of the developing neuroepithelium may suggest increased metabolic demand during development and maturation of the olfactory neuroepithelium, and postnatal retreat of capillaries to the underlying lamina propria may suggest diffusion of nutrients and gases from blood vessels into the lamina propria and direct gaseous exchange from the atmosphere.