Licence: Public Domain Mark
Credit: The anatomy of the human body / By J. Cruveilhier. Source: Wellcome Collection.
Provider: This material has been provided by the University of Massachusetts Medical School, Lamar Soutter Library, through the Medical Heritage Library. The original may be consulted at the Lamar Soutter Library at the University of Massachusetts Medical School.
887/944 (page 863)
![by the same nerve of the left side, and sometimes also by the right and left cardiac branches given off from the pneumogastric nerves in the lower part of the neck. The second anastomosis, or that which takes place in front of the trachea, above the right pulmonary artery, and behind the arch of the aorta, has been known, since the time of Haller, as the great cardiac plexus (magnus, profundus plexus cardiacus, Scarpa). A ganglionic enlargement is not unfrequently found at the junction of the principal branch- es. This great cardiac plexus is chiefly formed by the middle and inferior cardiac nerves of both sides : [it also receives part of the right superficial nerves.] Lastly, all the car- diac nerves end in the third set of anastomoses, namely, those upon the anterior and posterior coronary arteries around the root of the aorta. Great as the variety may be in the course and size of the cardiac nerves up to the origin of the great vessels from the heart, there is as constant a uniformity in their ar- rangement around those vessels, and in their ultimate distribution to the heart. Upon the origin of the great vessels, the cardiac nerves are arranged in three layers or sets. The superficial layer of nerves is the smallest; it occupies the anterior surface of the arch of the aorta, and especially its right side ; the nerves are visible without any dis- section through tiie transparent pericardium ; they all pass (y) to the anterior coronary artery, to the right side of the infundibulum of the right ventricle. In this superficial layer, the superficial cardiac plexus, may be included the ganglion of Wrisberg, when it exists, and its several branches, which in a great measure assist in forming the anterior coronary plexus. The middle layer of nerves is composed of two very distinct parts, viz., of the great or deep cardiac plexus of Haller, which is situated between the trachea and the arch of the aorta, above the right pulmonary artery ; and of a much smaller part, situated below the great cardiac plexus, from which it is derived, and between the right pulmonary artery and the arch of the aorta. In order to obtain a good view of this layer, the arch of the aorta must be cut through. The deep layer of iierves is situated between the right pulmonary artery and the bifur- cation of the trachea. The trunk of the pulmonary artery must be divided in order to expose it. The Anterior and Posterior Coronary Plexuses.—The whole of the superficial cardiac plexus or superficial layer of nerves ends in the anterior coronary plexus {v) which sur- rounds the right coronary artery. The middle and posterior layers unite below the right pulmonary artery, in front of the auricles, to form a plexus, which might more properly be named the great or deep cardiac plexus than the interlacement so called by Haller. From this plexus, into which the left inferior cardiac nerve enters directly, the follow- ing branches proceed; anterior auricular branches, which are very numerous ; certain branches which pass between the aorta and the pulmonary artery to gain the right side of the infundibulum, and join the anterior coronary plexus, which, as we have seen al- ready, is derived from the superficial cardiac plexus ; lastly, the branches for the poste- rior coronary plexus, which surrounds the origin of the left coronary artery, and divides, like that vessel, into two secondary plexuses, one of which runs round the left auriculo- ventricular furrow, while the other {v') enters the anterior ventricular furrow. The nervous filaments from these plexuses soon leave the ramifications of the arter- ies ; they proceed separately ; they are all equally small, and can be seen without any dissection, like white lines, extending from the base towards the apex of the heart. They all belong to the ventricular portion of the heart; a few of them, however, ascend on the posterior surface of the auricles, which are much more abundantly supplied upon their anterior surface. The cardiac nerves are not entirely distributed to the heart; several of them are lost in the coats of the aorta, some join the anterior pulmonary plexus, and some ramify in the pericardium. The Thoracic Portion of the Sympathetic System. In the thorax, the trunk of the sympathetic (*' t,fig. 302) consists, on each side, of a grayish cord, having as many nodules or ganglia upon it as there are vertebra;. This cord is situated, not in front of the dorsal vertebrae, but in front of the heads of the ribs, to which the ganglia for the most part correspond: the two superior thoracic ganglia are the largest, and are almost always united; the succeeding ganglia are almost of equal size, the twelfth being next in size to the first and second. The ganglionic struc- ture is observed throughout the whole extent of this part of the sympatlietic, so that the cords of communication between the ganglia may be said to be merely prolongations of the ganglia. In some subjects the ganglia cannot be distinguished from the portions of the sympathetic trunk above and below them, except by the branches which enter and converge from those points; it would, therefore, be a serious anatomical error to regard the portions of the trunk between the ganglia as mere filaments of communica- tion. In some subjects the cords between the ganglia are divided into two or three fila- ments. The varieties observed in the number of the thoracic ganglia are rather appa-](https://iiif.wellcomecollection.org/image/b21196801_0887.jp2/full/800%2C/0/default.jpg)
