I) Objective
The morphology of the terminate of the autonomic innervation in the nasal mucosa remains unelucidated as compared to the effect of its function.
It has been reported to be difficult to observe sympathetic or parasympathetic nerve fibers in search of peripheral autonomic nerve fibers by conventional plating method.
Recently, microscopic examinations for fine structures and histochemical studies have made it possible to observe both sympathetic and parasympathetic nerve fibers as adrenergic and cholinergic nerves. However, few papers have been published which describes in detail the mode of distribution of both nerve fibers in the nasal mucosa.
In the present study, innervation of the sympathetic and parasympathetic nerves in the mucosa of the human inferior turbinate was investigated histochemically by observing both nerves as adrenergic and cholinergic nerves, respectively, in the same specimen. The author studied the mode of their distribution and made comparison of the amount of distribution between them.
II) Methods
As the study subjects, 15 cases which required resection of the mucosa of the inferior turbinate were selected from cases having nasal diseases. From these cases nasal mucosal tissues were collected, fixed with freezing and prepared for histochemical examinations.
The sympathetic nervous system was treated by Falck-Hillarp's method and the parasympathetic nervous system by Karnovsky-Root's method.
In this study, a part of the specimens were further stained with Haematoxylin-eosin staining and mode of distribution of autonomic nerve fiber terminates and their relation with surrounding pathological tissues in order to make more accurate observation for innervation.
III) Results
(1) In the epithelial layer of the nasal mucosa, distribution of neither adrenergic nor cholinergic nerve fibers could be seen.
(2) In the tunica propria, both adrenergic and cholinergic nerve fibers were distributed abundantly. Typically, adrenergic nerve fibers formed reticular superficial nerve plexus in the superficial layer, while the superficial nerve plexus formed by the cholinergic nerve fibers was seen in parallel with the epithelial layer of the mucosa. When the amount of distribution was compared between other nerve fibers, little or no difference was seen for the whole tunica propria, suggesting innervation by both nervous system. However, for the lower layer of the mucosa the characteristics of distribution pattern reveal superiority of the cholinergic nerve fibers.
(3) In the glandular tissue, adrenergic nerve fibers were seen around glandular cell population, while they were not present between each glandular cells. On the contrary, cholinergic nerve fibers were distributed abundantly not only in the periglandular plexus but also in the area around each gland. Quantitative comparison demonstrated prevalence of cholinergic nerve fibers, suggesting superiority of parasympathetic innervation.
(4) Examinations for arteries and veins revealed pronounced formation of plexus of both nerve fibers around the tunica externa and interna of arteries. Similar findings were obtained for veins. However, for both arteries and veins no plexus was seen in the area corresponding to the intima. Thus, from observation for arteries and veins it was confirmed that they are innervated by not only adrenergic nerve fibers, as believed heretofore, but also cholinergic ones. Thus, findings indicating double innervation were obtained, which is supported by their functions. In the cavernous sinus, one of the characteristics of the inferior turbinates in humans, some differences were seen in the mode of distribution between these nerve fibers. However, nerve fibers entering into the smooth muscle layer of the tunica media were seen pronouncedly, suggesting double innervation.
抄録全体を表示