The research deals with the features of embryogenesis, morphogenesis and development of the relativity between space and time in the human sublingual gland (SLG). The realization of the aim and objectives of the scientific paper was achieved by studying the features of the anlage and the course of prenatal ontogeny in the human SLG in 29 human embryos, 60 pre-fetuses and 51 fetuses (total - 140 objects), whose death had not been related to diseases of the SLG and who had developed in the uterus not influenced by clearly expressed harmful factors of the external and internal environment.
A complex of morphological methods of investigation, which included: macroscopy, manufacturing and microscopy of series of consecutive histological and topographic anatomical sections of embryos (Em) and human pre-fetuses (Pf), the SLG of fetuses (Ft) of different age groups, common and fine preparation under the control of binocular magnifying glass, morphometry, producing graphic, solid plastic and 3-D (three-dimensional) computer reconstructive models as well as general histological, cytometric and lectinohistochemical, histochemical, biometric and statistical methods were used.
We were the first to study the features of morphogenesis and chronological sequence of the SLG growth, its spatio-temporal relationships during the prenatal period of human ontogenesis, variant and age anatomical variability, periods of intense and slow growth by means of a complex of morphological methods of investigation (cytology, histo- and lectin histochemistry, biometrics with different types of statistical analysis), that made it possible to obtain new scientifically substantiated data, which supplements substantially modern notions about regularities of ontogenetic chronology of human embryonic development. It was found that the anlage of the SLG appears for the first time at the end of the embryonic period in an embryo with 12.8 mm of the CRL (the 6th week of IUG), initially as a thickening in the epithelium of the primary oral cavity (the so-called epithelial plates), and then – as a curving (immersion) of the oral cavity bottom epithelium into the adjoining mesenchyma of the glosso-cellular furrows on both sides of the tongue's germ. The peculiarity of the morphological characteristics of the SLG in the early prenatal ontogenesis is its genetic ability to form independent lobes having their own excretory ducts.
It has been established that the formation and immersion of the gland germs into the adjacent mesenchyme and their transformation into epithelial taenia is due to the accumulation of sialylated glycopolymers (N-acetylneuramine acid), N-acetyl-D-glucosamine – specific to lectin (Lc) of a WGA (Wheat germ agglutinin) and Lc of SNA (Sambucus nigra); N-acetyl-2-deoxy-2-amino-D-glucopyranose screened with sialic acid of ß-D-galactose and α-L-fucose specific for Lc of HPA (Helix pomatia agglutinin), RCA (Ricinus communis) and LABA (Laburnum anagyroides) bark respectively. One can find these glycopolymers during the first 12 weeks of embryogenesis both on the cell membrane of the sublingual gland epithelial germ and in their cytoplasm. Accumulation of the receptors to these Lc on the basal membrane of the epithelial germ during the early prenatal ontogenesis of the sublingual gland is variable. We were the first to describe the location and to prove the effect of the sequential distribution of glycopolymers-Lc receptors in cells, on their surface and in extracellular tissue structures during the organ-specific differentiation of epithelial and mesenchymal germs of the SLG, the involvement of these molecules in the epithelio-mesenchymal interactions, which depend on their heterogeneous origin. The sequence of biosynthesis and activity of complexes of polysaccharide nature have been studied and their role in the rates of differentiation and structural transformations of the SLG and oral cavity with its derivatives in early prenatal ontogenesis has been confirmed.
Using the complex of the SLG research methods in the fetal period of human ontogenesis allowed us to conclude that the appearance of variants of the SLG forms in fetuses aged 4-10 months of the intrauterine development (81,0 - 375,0 mm of CRL) depends on the number of independent particles and their location relative to the basic germ of the gland. The anatomical variability of the SLG forms at the end of prenatal development is determined by ellipsoid, fusiform and discoid variants of the gland external shape. In the fetal period of human ontogenesis, there were 6 to 14 independent particles of the SLG with excretory ducts, which open as a kind of "chain" on the mucous membrane of the su
