ELECTRON-MICROSCOPIC OBSERVATIONS ON THE MUSCULAR COAT OF SWELL BODIES IN HUMAN NASAL-MUCOSA

Morphology and function of so-called nasal ''swell bodies'' or ''caver nous tissue'' have been studied by many investigators during the past 140 years. However, many details of this interesting and peculiar tiss ue remained unsolved, even though this vascular system plays an import ant role in a variety of rhinologic disorders. The present study descr ibes electron-microscopic details of the muscular coat of the differen t venous structures that form human nasal swell bodies. The specimens were taken from patients requiring removal of conchal mucosa and septo plasty; semithin and ultrathin sections were obtained and examined wit h the optical and electron microscopes. The histologic evaluation show ed differences in the venous wall structure depending on the location of the vessels. The muscular layers were significantly thinner in thos e parts of the swell bodies located adjacent to the epithelium. Electr onmicroscopic studies enabled us to determine the cytoplasmic componen ts of smooth muscle cells, i.e., thin filaments, glycogen granules, ca veolar plasmalemmal areas, cytoplasmic dense bodies (CDB), and membran e-associated dense bodies (MADB). Another interesting feature was the varying appearance of the basal lamina of smooth muscle cells of the c avernous tissue. Based on the findings of the present study, the morph ologic peculiarities of nasal swell bodies are compared and discussed with the appropriate literature. Further immunohistochemical and molec ular-biological studies will have to be performed to understand the co mplex functional mechanism of this unique vascular system.