Morphological features of the pons in human fetuses 14-15 weeks of intrauterine development

Abstract

Knowledge of human embryonic development is essential to improve our understanding of human fetal anatomy and for better understanding the etiology of congenital malformations. Currently, the structures of the posterior cranial fossa and the brain stem are of great interest to researchers, because of a large number of nuclei are located in the pons area, which play an important role in ensuring vital functions. The aim of the scientific work is to establish the morphological features of the pons of human fetuses at 14-15 weeks of gestation, the size and area of the nuclei of cranial nerves and neurons which are located in the area of the pons. Anatomical and histological research was carried out on 6 human fetuses aged 14-15 weeks of gestation. The cadaver material for research was obtained as a result of late abortions which were conducted according to medical indications in Vinnytsia maternity hospitals. Preparations were fixed in a 10 % solution of neutral formalin, stained with hematoxylin-eosin, toluidine blue modified by Nissl. Computer histometry (Toup View) was used for morphometric research. Statistical digital data were processed on a personal computer using Microsoft Excel 2016 and “Statistica 6.1” software. We established that in human fetuses at 14-15 weeks of intrauterine development, the nuclei of the trigeminal, abductor and vestibulocochlear nerves were detected. The nucleus of the facial nerve on 14-15 weeks of gestation is represented by single polygonal nerve cells with eosinophilic cytoplasm. The nucleus of the abductor nerve had the largest area, the cochlear nucleus of the vestibulocochlear nerve had the smallest area. The largest area of neurons was in the nuclei of the VIII pair of cranial nerve, the smallest – in the nucleus of the abductor and facial nerves. At 14-15 weeks of intrauterine development of human fetuses, the area of the cell nucleus could be determined only in the nuclei of the vestibulocochlear nerve, while the cell nuclei of the trigeminal, facial, and abductor nerves were represented by nerve cells of a spherical shape with a nucleus in which a basophilic nucleolus and a homogeneous eosinophilic cytoplasm were noted. Thus, in human fetuses of 14-15 weeks of intrauterine development, differences in the sizes and areas of the nuclei of cranial nerves and neurons that form nuclei in the pons area were found.