冠動脈神経支配の組織学的研究 : 左冠動脈主幹部分岐部付近より発する循環調節反射の求心性神経終末について

概要

論文の詳細を見る
Histological survey was conducted on the innervation of coronary arteries, with special reference to the afferent endings of the depressor reflex arising from the vicinity of bifurcation of the left coronary artery into the anterior descending branch and the circumflex branch.Method : Specimens were obtained from adult dogs. A modified Bielschowsky's silver stain was adopted.Results : 1) Rather thick nervous fibers were always found in a special locality in the adventitia and/or the media of the left coronary artery, in the vicinity of bifurcation into the anterior descending branch and the circumflex branch.These thich nervous fibers arborized abruptly into thin fibers which terminated finally in the muscular layer with free endinfis forming a ring, a brush, a nodule and so on.The structure of this ending was quite similar to those of the sinus nerve and the aortic nerve. On dissecting the vagi distally from the nodal ganglia, degenerative changes were always found in some parts of these thich nervous fibers in the left coronary artery.2) This and fine nervous fibers apparently forming networks were found within thin layers of connective tissue in the media of the proximal trunk of the left coronary artery. This sort of nervous structure was hardly found in the portion of coronary artery distal from the bifurcation. However, similar findings were observed in the aortic wall as well Discussion : It is suggested by these histological findings that the endings of the thick nervous fibers in the vicinity of bifurcation of the left coronary artery represent the afferent nerve coming through vagi. The physiological data which we reported previously suggest strongly that this is a barorecepcor of the depressor reflex which arises from the left coronary artery, especially in view of its localization.The possibility, that this ending conducts the sensation of pain, is unlikely, because it comes through vagi and not sympathetic pathway.As for the function of the network consisting of thin and fine nervous fibers in the proximal portion of the left coronary trunk, we might suggest a role as an afferect ending, because this network was localized in the connective tissue layer in the media, and not in muscle itself. Its exact function is not yet fully understood. In view of the presence of similar structures in the aorta, we would like to assume that this ending might represent another type of baroreceptor which consists of poorly myelinated or unmyelinated nervous fibers. The possibility that certain poorly myelinated or unmyelinated fibers play the role of afferent pathway was already suggested by one of our co-workers and others.Endings of poorly myelinated or unmyelinated nervous fibers should further be investigated in the future, especially in the peripheral parts of coronary, arteries, capillaries and heart muscles.Conclusion : 1) The afferent nervous endings which consist of rather thick nervous fibers and come through vagi, were found in the vicinity of bifurcation of the left coronary artery. These appear to represent baroreceptors of the depressor reflex arising from the left coronary artery which had been found by our physiological experiments.2) The nervous networks which consist of thin and fine nervous fibers were found in the proximal portion of the left coronary trunk. These are presumed to be another type of baroreceptors.
社団法人日本循環器学会の論文
1960-01-20

冠動脈神経支配の組織学的研究 : 左冠動脈主幹部分岐部付近より発する循環調節反射の求心性神経終末について

スポンサーリンク

概要

著者

関連論文

スポンサーリンク