MUCOSAL VASCULATURE OF HUMAN FETAL PALATE - A SCANNING ELECTRON-MICROSCOPIC STUDY OF CORROSION CASTS

The microvascular architecture of palatine mucosa was investigated in human fetuses aged from 18 to 21 weeks, with the use of corrosion cast ing and scanning electron microscopy. Three levels of blood vessels co uld be distinguished: (1) the subepithelial capillary network, (2) the mucosal arterioles and venules and (3) the periosteal/submucosal vess els. The subepithelial capillaries formed elongated loops on the crest s and slopes of transverse palatine ridges, low and irregular loops el sewhere in the hard palate and a flat network in the soft palate. This vascular pattern is markedly less complex than that observed in infan ts, although the general arrangement of blood vessels already resemble s that typical for the postnatal period. Weaker differentiation of the subepithelial vessels associated with connective tissue papillae in t he fetal palate probably results from the absence of physical stimuli which after birth are induced by sucking and mastication.