228 



LYMPHATIC AND LACTEAL SYSTEM. 



and from the rectum, take somewhat the 

 'course of the inferior mesenteric artery and its 

 branches; they pass through their appropriate 

 glands, and are ultimately received by the 

 lumbar glands. 



The vasa efferentia of the lumbar glands 

 cannot be said to receive the contents of all the 

 vessels and glands hitherto described ; they, 

 in fact, empty themselves into the principal 

 lymphatics by whose union the thoracic duct 

 is formed, or into the duct itself soon after its 

 formation. The principal lymphatics above 

 alluded to may be traced more or less dis- 

 tinctly from Poupart's ligament to the second 

 lumbar vertebra, where they usually unite to 

 form the thoracic duct, the vessels of opposite 

 sides communicating freely with each other. 



Their position and arrangement will be well 

 understood by the accompanying wood-cut. 



Fig. 56. 



In the dissection from which this wood-cut was 

 taken, the injection did not pass freely into the 

 glands, from which circumstance the vessels are 

 more distinctly seen, as it permitted the glands 

 which partly concealed them to be removed with- 

 out causing extravasation. These vessels, after 

 taking somewhat the course of the external, in- 

 ternal, and common iliac arteries, may be seen 

 to ascend pretty close to the inner edges of the 



psoffi muscles, to communicate freely by cross 

 branches, and opposite to about the third 

 lumbar vertebra to pass inwards, on the right 

 side behind the cava, on the left behind the aorta 

 to unite into one vessel on the body of the se- 

 cond lumbar vertebra, behind the root of the 

 right renal artery, and thus to form the com- 

 mencement of the thoracic duct. In the subject 

 from which the drawing was taken the branches 

 did not unite in the abdominal cavity. Two 

 nearly equal-sized vessels ascended into the 

 thorax, which, however, soon coalesced. The 

 union generally takes place opposite the abrupt 

 dilatation marked No. 11, and which would be 

 termed the receptaculum chyli, although the 

 lacteals generally enter above this point. 



The lacteals, properly so called, take origin 

 from the small intestines. During the process 

 of digestion they contain a white fluid, the 

 chyle, but at other times their contents are 

 colourless like those of the rest of the lympha- 



56. Shewing the principal lymphatic branchet 

 of the inguinal, iliac, and htmbar regions, 

 into which the vasa efferentia of the 

 glands of these regions empty themselves, 

 and by the convergence and union of 

 which the thoracic duct is generally 

 formed on the body of the second lumbar 

 vertebra. Shewing alto in this instance 

 an abrupt globular dilatation in the posi- 

 tion of the receplaculum chyli, and a 

 double thoracic duct. ( From a dissec- 

 tion. ) 

 a, The body of the second lumbar 



vertebra. 

 6, The right crus of the diaphragm. 



c, The It ft crus of the diaphragm. 



d, The abdominal aorta displaced. 



e, The diaphragm. 



f, Psoas muscle. 



1, Vasa effeientia of the inguinal 

 glands. 



2, Their vasa efferentia. 



3, The principal branches associated 



with the internal inguinal glands. 



4, Those accompanying the external 



and common iliac glands. 



5, Those accompanying the lumbar 



glands. 



6, The convergence of the vessels of 



opposite sides. 



7 and 10, The trunks from the left and 

 right sides, which in this instance 

 did not unite (as is usually the 

 case) to form the thoracic duct, 

 but passed separately into the ca- 

 vity of the thorax. 



8, Transverse communications be- 



tween the vessels of opposite sides. 



9, A communication between the 



transverse branches in the vertical 

 direction. 



11, The receptaculum chyli, in this 

 instance remarkably abrupt, and 

 of a globular form. 



tic system ; they are joined by the lymphatics 

 of the caput coli, the ascending and transverse 

 colon ; they also communicate with the lym- 

 phatics of the 

 stomach. The 



the lacteals commence from the villi and from 

 the spaces between the villi in the small intes- 

 tines, not by open mouths, but by a delicate net- 

 work of vessels, through the coats of which 



liver, spleen, pancreas, and 

 more modern opinion is, that 



