VEIN. 



at nearly right angles, of the externa and internal, are very 

 confiderablc venous trunks, difTering (lightly on the right 

 and left iides of the body. The right is much the fhorteft, 

 and proceeds obliquely behind, and rather above its cor- 

 refpondnig artery. The left, placed behind and below the 

 left common ihac artery, •proceeds obliquely upvrards and 

 towards the right, acrofs the front and upper part of the 

 facrum ; then goes between the fifth lumbar vertebra and the 

 right common ihac artery, to join its correfponding vein, 

 at an acute but open angle, on the rigiit fide of the vertebral 

 column, at the interval between the fourth and fifth lumbar 

 vertebri- ; forming by this union the great trunk of the in- 

 ferior or afcending vena cava. 



One or two lumbar veins fometimes jein tlie common 

 iliac. The facra media, a fmall vein, terminates, either at 

 the angle of union, or in the left common ihac. 



The inferior vena cava lies at its origin, clofe to the 

 aorta, on its right, and on the right fide of the vertebral 

 column ; it afceads in the fame relative pofition, firft con- 

 iiefted to the fpine, then to the right cms of the diaphragm, 

 but more and more dillant from the aorta, as it rifes higher 

 in the body. It leaves tiie vertebral column towards the 

 upper part of the abdomen, and enters a deep fiiTure in the 

 pofterior or thick edge of the liver, which covers two-thirds, 

 and fometimes the whole vein. From the loins upwards the 

 fize of the trunk is confiderably increafed : it will eafily ad- 

 mit a large thumb. Quitting the liver, it penetrates the 

 tendon of the diaphragm (fee Diaphragm'), and imme- 

 diately opens into the right auricle of the heart. (See 

 Heart.) In its palFage it receives the following veins. 



1 . The facra media has been already mentioned. 



2. The lumbal- veins correfpond to the arteries of the 

 fame name, and return the blood from the parts fuppbed by 

 thofe veffels. They form about four trunks on each fide, 

 which end in the lateral and pofterior part of the inferior 

 cava. 



3. The fpermatic veins. They come from the tefticles in 

 the male fubjeft, from the uterus and ovaria in the female ; 

 receive various branches from the ureter ( uretericas ) , fat of 

 the kidney (adipofae), &c. and communicate with veins in 

 the mefentery and mefocolon ; form firft a confiderab'le 

 plexus, with feveral trunks communicating together, and 

 afterwai-ds a fingle vein, which ends in the front of the vena 

 cava on the right fide, and in the renal vein on the left. 



4. Renal or cmulgent veins. Of thefe large trunks, the 

 riglit is much fhorter than the left, on account of the rela- 

 tive pofition of the vena cava and the kidneys. The latter 

 erodes the vertebral column in front of the aorta. There 

 are rarely more than one on each fide. 



5. Capfular veins. Thefe often end in the renal, particu- 

 larly on the left fide, otherwife they terminate in the cava. 



6. Hepatic veins. They are numerous, and of different 

 fizes. Ufually there are from three to five large ones, and 

 feveral fmaller. They return the blood of the vena portarum 

 and that of the hepatic artery. 



7. Inferior diaphragmatic veins ; accompanying the ar- 

 teries, and ending either in the cava, or in an hepatic vein. 

 Soemmerring ftates that fome diaphragmatic veins join the 

 vena portarum. 



Befides the works to which we have referred in the courfe 

 of this article, for plates illuftrating particular veins, we 

 may refer in general to the FafcicuH of Haller, to the plates 

 of the veins in Loder'scolleftion,and to Mayer's Anatoraifche 

 Befchreibung der Blutgefiiffe des menfchlichen Korpers ; 

 mit kupfern, 1788, 8vo. See alfo Walter Angiologifches 

 Handbuch, 1779- Soemmerring, De Corporis Humani 

 Fabrica, t. 5. Bichat's Anatomie Defcriptive, t. 4. 



Veins, Difeafcs of the. Veins (fays Mr. Hodgfon) are 

 liable to all thofe morbid changes which are common to foft 

 parts in general ; but the membranous Uning of thefe veffels 

 is pecuharly fufceptible of inflammation. When a vein is 

 wounded, the inflammation, which is the cffeft of the injury, 

 fometimes extends along the lining of the vefTel into the prin- 

 cipal venous trunks, and, in fome inftances, even to the 

 membrane which lines the cavities of the heart. This inflam- 

 mation fometimes produces an effufion of coagulating lymph, 

 by which the oppofite fides of the vein are united fo as to 

 obliterate the tube. In this manner, a great extent of the 

 veffel is occafionally converted into a folid cord. In fome in- 

 ilances, the fecretion of pus into the cavity of the veffel is 

 the confequence of inflammation of the membranous lining 

 of veins : under thefe cii-cumftances, the matter is either 

 mixed with the circulating blood, or the inflammation, having 

 produced adhefion of the fides of the veffel at certain inter- 

 vals, boundaries are formed to the coUeftions of pus, which 

 in this manner form a chain of abfceffes in the courfe of the 

 veffel. 



When the inflammation of veins is not very extenfive, its 

 fymptoms are the fame as thofe of local inflammation in ge- 

 neral ; but when the inflammation extends into the principal 

 venous trunks, and pus is fecreted into the veffel, it is ac- 

 companied with a high degree of conftitutional irritation, 

 and with fymptoms which bear a ftriking refemblance to 

 thofe of typhus fever. See Hodgfon's Treatife on the Dif- 

 eafes of Arteries and Veins, p. 511, 512, 



In the firft volume of the Tranfaiftions of a Society for 

 the Improvement of Medical and Chirurgical Knowledge, 

 Mr. Hunter has publiftied an extremely interelling paper on 

 the fubjeft of inflammation of veins, and he has particularly ad- 

 verted to that common cafe, an inflamed arm after bleeding. 

 By fome, he obferves, this complaint has been imputed to the 

 wounding of a tendon ; by fome, to the injury of a nerve ; 

 and by others it has been afcribed to a bad conftitution. 



Mr. Hunter expreffes his doubts of the accuracy of thefe 

 opinions, and he remarks, that the manner in which thefe 

 fore arms come on, plainly proves that they arife from the 

 wound not heahng by the firft intention ; for, in moft 

 cafes, the external wound firft fellers or inflames, and 

 then fuppurates or ulcerates, the cavity of the vein be- 

 coming fubfequcntly impervious. In fome inftances, this 

 fuppuration is only fuperficial, the vein and parts below 

 having united. In other examples, the lliin appears to 

 be united, but not clofe to the vein, fo that a fmall ab- 

 fcefs forms between the veffel and the integuments. This 

 burfts and difcharges a thin watery fluid, and no further 

 mifchief happens. When, however, this imperfection of 

 union is continued on to the cavity of the vein, this veffel 

 inflames both upwards and downwards, frequently to a con- 

 fiderable extent, and the furrounding parts join in the in- 

 flammation. 



We find, fays Mr. Hunter, all thefe variations in different 

 cafes. Sometimes the difeafe goes no further than an in- 

 flammation near the orifice of tlie vein, and the cafe often 

 ends in refolution. At other times, the inflammation is 

 carried further, but fuppuration is prevented by the adhefive 

 inflammation taking place in the affefted portion of the vein, 

 and, in fuch cafes, the veins may be plainly felt, like hard 

 cords, after the furrounding tumefaftion has fubfided. But 

 this falutary effeft is not always produced, and fuppuration 

 in the vein is the conlequence, but often in fo limited a de- 

 gree, that only a fmall abfcefs forms in the cavity of the 

 vein, near the punfture. The confinement of the matter in 

 this part of the vein, arifes from adhefions in the veffel, a 

 little above and below the orifice. But, in many cafes, 

 4 S 2 adhefions 



