224 



LYMPHATIC AND LACTEAL SYSTEM. 



hernia, he unsparingly divides the principal 

 lymphatics and glands in the inguinal region. 

 In the next place these vessels vary so 

 much in number, and consequently in position 

 in different individuals, while there exist so 

 many parts, where their presence is rather 

 presumed than demonstrated, that a general 

 outline of their course is all that can be re- 

 quired or depended upon. In the distribution 

 of these vessels two principal objects are spe- 

 cially provided for; the conveyance of the 

 lymph to its appropriate glands, and after- 

 wards from them to the two trunks of the sys- 

 tem. We, consequently, first notice an evident 

 tendency of the vessels from the structures in 

 which they take origin towards the glands 

 which intervene between them and the trunks 

 of the system ; secondly, their necessary course 

 from these glands to the trunks themselves. 



With this key to the, distribution of these 

 vessels, I propose to describe, first, the posi- 

 tion of the glands, then to treat of the trunks 

 of tlie system ; and, lastly, having these two 

 fixed points, to trace the vessels throughout their 

 course. 



In the lower extremities the conglobate glands 

 are chiefly found in the inguinal region, where 

 they are divided into a superficial and deeper 

 seated cluster; a few small glands are situated 

 in the popliteal space surrounding the bloodves- 

 sels. We rarely meet with one between the 

 popliteal space and the inguinal region, and they 

 are only occasionally met with below the knee, 

 and then isolated and extremely small. In the 

 upper extremity the large and clustered lym- 

 phatic glands are only found in the axillary 

 space; a single gland is generally located just 

 above the internal condyle of the humerus ; 

 below this point a distinct gland is rarely met 

 with. 



In the cervical region the principal lympha- 

 tic glands are situated in two cellular intervals, 

 found at the upper part between the omo-hyoid 

 and sterno-cleido-mastoid muscles, and below 

 between the latter muscle and the trapezius. 

 The glands in these positions are ranged in a 

 line so as to form a sort of chain of glands, 

 hence the term glandulae concatenate as applied 

 to them. 



On the head and face the glands are few, 

 small, and isolated. One may be pretty con- 

 stantly met with behind the ear over the mas- 

 toid process of the temporal bone, another in 

 front of the ear in the neighbourhood of the 

 parotid gland. One or two will be found 

 under the margin of the lower jaw, both in the 

 median line and also more laterally situated. 

 A small lymphatic gland will usually be distin- 

 guished amonst the numerous but small buccal 

 and labial glands. 



In the cavity of the cranium no lymphatic 

 glands have been discovered, but in the abdo- 

 minal and thoracic cavities they are very nume- 

 rous. In the abdomen they are chiefly situated 

 in the neighbourhood of the larger bloodvessels. 

 In the pelvic region they form clusters, or rather 

 chains of glands accompanying the external, in- 

 ternal, and common iliac vessels, and in the 

 lumbar region they are similarly arranged on 



either side of the aorta, as high as the point of 

 origin of the superior mesenteric artery. 



The absorbent glands which intercept the 

 lacteals in their course towards the receptaculum 

 chyli are large and numerous; they are situ- 

 ated between the folds of the mesentery, and 

 accompany the trunk and some of the branches 

 of the superior mesenteric artery ; they are 

 usually termed mesenteric glands. The remain- 

 ing lymphatic glands of the abdominal viscera, 

 though numerous, are smaller and more isolated ; 

 they will generally be found close to the arteries 

 of the viscera to which they belong, and conse- 

 quently between the folds of the peritoneum. 

 Of this description may be considered those 

 accompanying- the hepatic and splenic vessels : 

 the coronary and gaslro-epiploic arteries of the 

 stomach, the small glands of the mesocolon or 

 epiploon, those associated with the renal or 

 spermatic arteries. 



The largest absorbent glands of the thoracic 

 cavity are those which receive the lymphatics 

 from the lungs ; they are situated at the roots 

 of the lungs, pretty closely attached to the 

 bronchi ; they are generally of a dark colour 

 and are called bronchial glands. Those asso- 

 ciated with the lymphatic vessels of the heart 

 are few and small ; two or three may generally 

 be noticed of the size of millet-seeds on the 

 aorta and pulmonary artery, where these vessels 

 are invested by the pericardium. In the poste- 

 rior mediastinum close to the thoracic duct 

 three or four large lymphatic glands are usually 

 met with, as well as several smaller ones in the 

 intercostal spaces, not far from the thoracic 

 duct. In the anterior mediastinum also some 

 small glands may be observed imbedded in 

 loose cellular tissue in the neighbourhood of 

 the internal mammary vessels. Occasionally 

 a small gland may be seen on the convex sur- 

 face of the diaphragm. 



In the substance or parenchyma of the dif- 

 ferent organs no lymphatic glands have been 

 detected. They have never been seen in the 

 brain, spinal marrow, in the lungs, liver, spleen, 

 kidney, or testicles, in nerve, muscle, or bone. 



Having given this general outline of the 

 position of the lymphatic glands, I shall now 

 proceed to describe the trunks of the system. 



The thoracic duct, (jig. 53,) or principal 

 trunk of the lymphatic system, generally com- 

 mences on the body of the second lumbar 

 vertebra pretty exactly in the median line, 

 concealed behind the root of the right emul- 

 gent artery, bounded on the right by the right 

 crus of the diaphragm, and to the left by the 

 aorta, to which it is connected by cellular tissue. 

 It may be said to be formed by the union of 

 the lymphatics of the lower extremities with 

 the trunks of the lacteals proceeding from the 

 intestines. At the conflux of the principal 

 vessels from these three sources, and there may 

 be more than one from each, a dilatation is 

 sometimes found, which has been called the 

 receptaculum chyli. From the body of the se- 

 cond lumbar vertebra the thoracic duct ascends 

 into the thorax between the aorta and vena 

 azygos. In the thorax it is situated behind 

 the right pleural fold of the posterior medias- 



