Japanese Journal of Veterinary Research;第1巻 第4號



古畑, 北雄

Permalink : http://hdl.handle.net/2115/11356
JaLCDOI : 10.14943/jjvr.1.4.167


Since BURNS (1811) many works have been published about swelling at the root of Art. carotis interna. Some authors treated it as pathological deformation, and others as normal structure sui generis. After HERING (1924), who had established so-called HERINGS Sinus Reflex Theory, there appeared many physiological, pharmacological or neurological studies accompanied by anatomical and histological investigations about this region. But most of the previously reported work was done with human materials and it was concerned mainly with nervous elements of this part. These are reasons why the author attemped the present work from the viewpoint of comparative anatomy. The following were results obtained with materials out of 40 dogs (Table 1). (1) Results of submacroscopic observations. a) The Sinus arteriae carotidis internae (=SACI) of healthy dog killed by bleeding did not very remarkably swell up in fresh or fixed condition in situs, as many previous authors had reported. b) However, it was easy to make it swell up with pressure injected through Art. carotis communis of fresh material in situs (Fig. 1). So it was proved that SACI of living dog was in a swollen state. Such difference of SACI shapes between the living and the post mortal condition was also supposed to be due to the contractile property of SACI wall and the blood pressure exerted upon it. c) Even by the pressure of added materials the diameters of SACI of dogs were less than those of Art. carotis communis and Art. carotis exierna, but were far greater than those of Art. carotis interna (Table 2). (2) Microscopical findings about SACI. a) In general, intimae of SACI wall were somewhat thicker than those of other arteries, and in several cases they were so remarkably thick as to indicate hyperplasy (Fig. 5). b) In subendotherial connective tissue there were seen less or more developed longitudinal smooth muscle fibres in many cases (Fig. 5). c) The whole thickness of SACI wall mainly depends upon that of the media. Media of SACI wall were far thinner than those of Art. carotis communis, Art. carotis externa and Art. carotis interna (Table 4). d) The elastic lamellae in media of SACI resembled those of the elastic type arteries, but they consist of only 7-10 layers; each lamella sends out many thinner blades and fibres to relatively wide interlamella spaces forming networks by anastomosis (Fig. 4). e) The muscle fibres of media of SACI wall were ring smooth muscles. The present author could not recognize any longitudinal or transversal fibres as WOLHYNSKY had seen in human materials (Fig. 5). f) Each smooth muscle fibre of media was separated from any other, and each fibre was inserted into elastic fibres and thinner elastic lamellae (Fig. 5). (3) The microscopical features of the upper part of Art. carotis communis of dog when examined proved to be the intermediate type, but it rather resembled the muscle type except the presence of large meshed networks of relatively large elastic fibres or lamellae within the media (Fig. 2). Art. carotis externa was similar to Art. carotis communis alternatively gradually to muscle type upwardly. Art. carotis interna indicated itself as the completely muscle type of artery (Fig. 7). (4) In the transitory part of Art, carotis communis to SACI there was seen no gradual transformation but sudden change of structure from the intermediate type to the elastic type of SACI. Within a short distance there was seen the feature of mosaic type of artery (Fig. 3). Between Art. carotis interna and SACI there was also similar transformation of mosaic feature (Fig. 6). (5) The author could not find any structure similar to that of SACI wall in his examinations of many other main arteries of dog body, with the exceptions of root regions of Art. occipitalis and another small artery (supposed to be Art. pharyngica ascendens) (Table. 3). Also there was not found any mosaic feature of transitory part, excepting only one case of the root of Art. coeliaca (