MORPHOMETRIC PARAMETERS OF THE HUMAN FETUS PONS 17-18 WEEKS OF INTRAUTERINE DEVELOPMENT

Abstract

Relevance. Currently, increased interest is observed in the early stages of postnatal ontogenesis in research of age-related changes in the systems of the human body. Aim: To define the macrometric parameters of the pons of human fetuses of 17-18 weeks of fetal development, the sizes and area of the cranial nerve nuclei contained in pons, as well as the size and area of the nerve cells that form these nuclei. Materials and methods: We performed an anatomical and histological examination of 10 human fetuses at the stage of 17-18 weeks of intrauterine development. Results: The boundaries of the nucleus of the abductor nerve are unclear, the neurons of the nucleus are spherical or rounded in shape. The vestibular nucleus of the vestibulocochlear nerve has an indeterminate shape, the boundaries of the nucleus are not clear, neurons with different areas of the nucleus are noted, from large to small. The motor nucleus of the facial nerve has an elongated shape, with not clear outer edges, the nerve cells are dome-shaped. The principal nucleus of the trigeminal nerve has a rounded shape. Conclusions: We established that at 17-18 weeks of intrauterine development of human fetuses, the nucleus of the abductor nerve, the motor nucleus of the facial nerve, the principal nucleus of the trigeminal nerve, and the vestibular nucleus of the vestibulocochlear nerve were visualized. Nucleus of the abductor nerve has the largest area, the smallest -has the vestibular nucleus of the vestibulocochlear nerve. The largest area of neurons of the vestibular nucleus was established in comparison with the area of the nucleus of the facial, trigeminal and abductor nerves. The diameter and area of the nuclei of the cells of the abductor nerve, the motor nucleus of the facial nerve, and the principal  nucleus of the trigeminal nerve have almost the same size, while the area of the neurons of the vestibulocochlear nerve is different, there is a group of neurons with a large area, and there is a group with a much smaller area of neurons.