HEART. 



597 



smaller veins, runs along the posterior surface 

 of the left ventricle, between the obtuse margin 

 and posterior longitudinal groove. The first 

 of these is frequently described as the trunk of 

 the vein, and it commences at the apex of the 

 heart, where it anastomoses with the smaller 

 posterior and anterior veins. It runs upwards 

 in the anterior longitudinal groove along with 

 the left coronary artery, gradually increasing in 

 size as it ascends, from the junction of the other 

 veins. \Vhen it reaches the base of the ventri- 

 cles it changes its direction, enters the groove 

 between the left auricle and ventricle, leaves 

 the coronary artery, passes from left to right in 

 the posterior part of the same groove, when it 

 becomes considerably dilated (sinus of the co- 

 ronary vein). It then opens into the right 

 auricle at its lower and back part close upon 

 the posterior edge of the septum auriculorum. 



Smaller posterior coronary vein (vena coro- 

 naria corclis minor). It commences at the 

 apex of the heart, runs up in the posterior lon- 

 gitudinal groove, or a little to its right side, and 

 receives its blood principally from the right 

 ventricle. It generally joins the sinus of the 

 coronary vein ; at other times it enters the auri- 

 cle separately immediately by the side of the 

 great coronary vein, so that its aperture is also 

 covered by the coronary valve. 



Smaller anterior coronary veins (ven<e inno- 

 minate of Vieussens). These are very small 

 and variable in number, and are placed on the 

 anterior surface of the right ventricle. One of 

 these, larger than the others, (generally the su- 

 perior,) sometimes receives the name of ante- 

 rior vein of Galen. They frequently unite to 

 form a single trunk ; more generally perhaps 

 they continue separate, pass in front of the right 

 coronary artery as it lies in the auriculo- ventri- 

 cular groove, and enter the right auricle at its 

 anterior and inferior part. One of the musculi 

 pectinati overlaps their entrance, forming a kind 

 of valve. 



Vena minim*, or veins of Thebesius, are 

 minute veins, which enter the auricle at various 

 points. It was maintained by Vieussens, The- 

 besius, and Ruysch, that some of the coronary 

 veins opened into the left side of the heart, 

 thus producing a slight intermixture of the dark 

 blood with the arterial. This has been more 

 lately asserted by Abernethy,* and has been 

 supposed to occur more frequently in phthisical 

 cases ; the difficulty of transmitting the blood 

 through the lungs causes their enlargement. 

 Such injections are liable to great fallacy, from 

 the great facility with which fine injections, or 

 even coarse injections when forcibly pushed 

 into the vessels, escape into the cavities of 

 organs. Especial care is, therefore, required in 

 conducting them. Notwithstanding that we 

 have the authority of some of the most accurate 

 anatomists in favour of this opinion, it is very 

 doubtful if any of these veins open into the left 

 side of the heart.f 



* Philos. Trans. 1798. 



t Professor Jeffray (Observations on the Heart, 

 &c. of the Foetus, p. 2) mentions a case in -which 

 the large coronary vein opened into the left auricle. 



Sinus of the coronary vein. This is always 

 described as a dilatation of the large coronary 

 vein, but I have found it decidedly muscular in 

 man and in several of the Mammalia, as the 

 dog, horse, ox, and sheep ; and it presents the 

 appearance of a muscular reservoir placed at 

 the termination of this vein, similar to the auri- 

 cles at the termination of the two cavae. This 

 sinus is placed in the posterior part of the 

 groove between the left auricle and ventricle, 

 adheres intimately to the outer surface of the 

 auricle, and communicates by one extremity 

 with the auricle, and by the other with the 

 large coronary vein. The commencement of 

 the dilatation is generally abrupt, and the first 

 appearance of the muscular fibres well defined. 

 I have seen it vary from two inches to only 

 half an inch in length. These muscular fibres 

 are generally circular ; part of them, however, 

 are oblique. Some of them belong exclusively 

 to the vein ; a great part appear to be connected 

 with the muscular fibres of the auricle. This 

 muscular sinus must serve to prevent regurgi- 

 tation along the coronary veins. I have also 

 generally found a distinct valve at the termina- 

 tion of the coronary vein in the sinus. This 

 valve resembles the valves found in the veins 

 of the extremities. It is generally single, some- 

 times it is double. I have also occasionally 

 found one or more single valves in the course 

 of the vein.* A distinct valve may also occa- 

 sionally be seen at the termination of the pos- 

 terior coronary vein in the sinus. Portal f 

 mentions that he has seen the coronary valve 

 situated in the interior of the vein a little from 

 its mouth. Thebesius and Morgagni have ob- 

 served valves placed in some of the smaller 

 veins where they terminate in the larger. The 

 valves of the coronary veins do not in general 

 prevent the passage of injections contrary to the 

 course of the blood along them. 



Lymphatics of the heart. The lymphatics 

 of the heart are divided into two sets super- 

 ficial and deep; the superficial commencing 

 below the external serous membrane, and the 

 deep upon the internal membrane. They fol- 

 low the course of the coronary vessels. Some 

 of them pass directly into the thoracic duct, 

 and, according to Meckel, sometimes directly 

 into the subclavian or jugular veins. O there 

 pass into the lymphatic glands situated in front 

 of the arch of the aorta, while others pass into 

 the glands situated around the bifurcation of 

 the trachea, and a few also join the lymphatic 

 vessels of the lungs. 



Pericardium. The pericardium is a fibrous 



Lecat (Mem. de 1'Acad. des Scien. 1738, p. 62) 

 found the coronary veins in a young child unite 

 themselves into a single trunk and enter the left 

 subclavian. It is probable that Soemmerring had 

 this case in view when he states, " Rarissime vena 

 haec in vena subclavia dextra finitur/' (de Corp. 

 hum. fab. torn. v. p. 340, 1800.) particularly as 

 Haller, (Element. Phys. torn. i. p. 375, 1757), in 

 quoting the case, has inadvertently substituted the 

 word dextra for sinistra. 



* I have seen two or three pair of double valves 

 in the course of the coronary vein in the horse and 

 ass. These animals have noThebesian valve. 



t Anatomic Mcdicale, torn. iii. 



