Macroscopic anatomy of the fetal nasal cavity

Abstract

Objectives to describe the macromicroscopic anatomy of the nasal cavity in the intermediate fetal period of human ontogenesis. Material and methods. The object of the study was horizontal histotopograms of the nose of 15 fetuses of both genders at the age of 1922 weeks of the intermediate fetal period of ontogenesis. The study used the method of macromicroscopic preparation, the modified method of saw cuts according to N.I. Pirogov, and the histotopographic method. Results. On the horizontal histotopographic sections the external nose was shaped like a triangle. The structures of the external nose were covered with skin soldered to the underlying tissues. In soft tissues, there was a large accumulation of arterial and venous vessels, nerves, and glands. In the intermediate fetal period, the nasal passages had the shape of a triangle, with the base turned to the nasal part of the pharynx. It was found that the anterior-posterior size of the nasal septum in fetuses of the intermediate fetal period was 14.054.34 mm, with a range of fluctuations from 5.75 to 19.85 mm. The anterior-posterior size of the nasal septum in female fetuses was greater than the anterior-posterior size of the septum of male fetuses. The value of the width of the nasal septum was the maximum in the lower third, and reached up to 2.540.67 mm. The narrowest part of the nasal septum was its middle third, the value was 1.630.47 mm. The areas of the nasal passages had no bilateral differences. Conclusion. In the intermediate fetal period there is the establishment of qualitative and quantitative macromicroscopic anatomy of the nasal cavity. All the main structures are determined: the nasal septum, nasal conchs, mucosa, and blood vessels. Sexual differences begin to form, and there are no bilateral differences. Quantitative characteristics of the structures of the nasal cavity in fetuses can serve as a justification for early surgical intervention in choanal atresia.