成人口唇外皮部の神經分布に就いて

On the Innervation of Pars cutanea of the lip in the adult

緒言

　口唇外皮部の神經分布に關する系統的な組織學的研究は未だ何人にも行われなかつた。唯部分的研究ではあるが，口唇外皮部では重大視す可き毛髪に關する知覺神經終末の研究は既にSzymonowicz （1909）及（Kadanoff　（1927—28）に依つて發表された。前者はメチレン青染色法により神經終末様式を追及して之を3種に區別した。後者はBielschowsky氏鍍銀法に依り屡々毛髪外根鞘内まで進入して終止する上皮内神經の存在を指摘した。

　斯くして本問題に就いては知覺性毛髪神經の終末に關する限り其研究成果には大いに見る可きものがあつたが然し尚お疑問視さる可き點も少なからず殘された。之は要するに染色法の不備と檢鏡上の不正確とに基いたものと思考される。そこで我々は口唇外皮部の毛髪に對する知覺終末は勿論，其他の知覺終末更に植物神經の分布状態をも闡明にす可く，材料を成人口唇にとり，之を矢状及前頭斷となし，當教室使用の銀銀法による多數の優秀な組職標本を作製，之を詳細に檢鏡し，次のような成果を收めることが出來た。

The followings are the results of the investigation on this theme by Seto's silver impregnation.

Of the sensory nerve elements for the cutaneous part of the lip in adult, the small parts advance int the stratum papillare and pass into simply formed, bra-nched terminations, as seen also in the scalp while the greater parts terminate as so-called hair-nerves chiefiy in the special tissue, which lies in the neck of hair follicle.

The development of the hair-nerves and their terminations, which runs parallel with that of the above described special tissue, is in this part much more remarkable than in the scalp. Because this special tissue is in the latter represented chiefiy as one-sided hair-neureshield (Seto), while in the former mostly as hair-neurotube, which surrounds the outer root--sheath completely.

The terminal formation of the sensory fibres, which euter the special tissue, is carried out in this part generally so complicated, that thrre is scarcely seen such a simple formation, for instance, as indefinite terminations, which are often seen in the scalp, but we recognize chiefiy the existence of such a complicated formation as plexus-like or saw-like te-rminations and sometimes mixed form of this both terminations, and what is more, they are formed more complicated than the same terminations in the sealp.

Furthermore, it is mentioned as a remarkable fact, that in the cutaneous part near the border of the lip there are seen the plexus-like terminations of sen-sory nature ending in the special tissue surrounding the outer hair-sheath, which has a very delicate hair despite having a strong developed sebaceous gland. And they develop much stronger than the above deseribed termination. Besides it is seen, too, that the sensory fibres, which arise from this terminations, sometimes form the secondary plexus-like termina-tions in the surroundings of the upper, outer hair-sheath.

The intraepithelial fibres in the outer hair-sheath. by Kadanoff, as well as the tactile cells and the-intraepithelial fibres ending in them by Szymonowioz are never recognized by our study.

The innervation of the vegetative nerves of this cutaneous part is quite in agreement with the case of the general skin. Their termination is represented as the terminal reticulum (Stöhr), which innervates all the various cells chiefly by contact.