ANATOMICAL PECULIARITIES OF THE NASAL PASSAGES IN 7-8-WEEK PRE-FETUSES

Abstract

In Ukraine due to an increasing harmful effect of environmental factors on the human organism, especially in the period of the intrauterine development, the problem has become an important issue. Investigation of the dynamics of changes in the topography of structures of organs and complexes of organs during the prenatal period of human ontogenesis with the aim to determine the interrelations and interaction of the shape-generating processes on the spatial-temporal orientation of the anatomical structures as well as finding the time and morphological preconditions of possible occurrence of variants in their structure and congenital defects is one of the important scientific directions in anatomical field. 10 specimens of the nasal area of 7-8week pre-fetuses, regularities of their development, formation and morphological transformations of the human nasal septum were examined by means of micro- and morphometry. During the pre-fetal period the rudiment of the nasal septum was found to be presented by the mesenchyme covered externally with the high columnar epithelium with the nuclei of a spherical or oval shape. The mesenchyme cells are located more densely in the central part of the nasal septum rudiment forming an aggregation. The anterior and median thirds of the nasal septum are merged with the primary palate, and its posterior part hangs down into the primary oral cavity. In pre-fetuses at the end of the 7th week of development (19,5-20,0 mm long) the subepithelial blood network is presented by the vascular columns of a capillary type 8,0±0,5 mcm in diameter. During the 8th week of the intrauterine life a layer of the subcartilaginous tissue appears in the central part of the nasal septum due to differentiation of the mesenchyme cells. The mesenchyme cells are concentrated directly near the lower part of the posterior third of the nasal septum looking like a pair formation in the form of laminae – vomer rudiment. At the end of the 8th week of the intrauterine development the subcartilaginous tissue of the nasal septum is transformed into the immature cartilaginous tissue. The rudiment of the cuneopalatine artery (24,0±0,5 mcm in diameter) is also determined in the posterior portion of the lateral wall of the primary nasal cavity.