THE MUCOUS GLANDS OF THE DEVELOPING HUMAN NOSE

Abstract

The nasal glands of 10 human embryos ranging from about 11 to 21 weeks of fetal age were studied in PAS-stained whole mounts; the nasal sulci of 2 term embryos, and histological sections of one early embryo, were also studied. Together, these indicate that: Goblet cells show histologically in the nasal epithelium before the anlagen of the gland acini begin to invaginate. By the 11th week there develops within each fossa a series of about 18 or 20 quite long (up to 8 mm) tubules. These originate at the anterior limit of the mucosa at the cutaneous junction, encircle the vestibule, are quite evenly spaced, run parallel to the surface, and end as blind bulbs. They are the prospective primary acini. At this stage they do not stain positively with PAS but stain a clear blue-violet. A scattering of brilliantly PAS-positive goblet cells is present in the epithelial area of the ductules. From the 11th to at least the 20th week, the mouths of the primary gland ducts remain in the muco-cutaneous junction area, while the developing acini are pulled posteriori as the face grows. The ducts reach a length of at least 2.24 mm by the 16th week. Between the 11th and 21st week a succession of short tubules, also terminating in blind bulbs, develops rapidly, first in the midfossa, then in the posterior and nasopharyngeal areas. These ductules are at right angles to the surface and are the prospective secondary acini. The development and distribution of the acinar glands seems to be related to the development and distribution of the arteries. The acinar glands and ducts begin to show strongly PAS-positive contents, presumably mucus, by the 16th fetal week. From then until the 21st week the acini show increasing complexity and staining intensity but apparently do not significantly increase in total number. By the 21st fetal week the mucosal vestibule is encircled by a nearly solid battery of mucus-producing organs, made up of densely packed goblet cells and the duct mouths of primary and secondary acini. The gross sulci of the mucosal surface of the septa and lateral walls are aligned in rows which apparently conform to the direction of ciliary flow.