|Henry Gray (18251861). Anatomy of the Human Body. 1918.|
|the front of the vertebral column, on the right side of the aorta, and, having reached the liver, is continued in a groove on its posterior surface. It then perforates the diaphragm between the median and right portions of its central tendon; it subsequently inclines forward and medialward for about 2.5 cm., and, piercing the fibrous pericardium, passes behind the serous pericardium to open into the lower and back part of the right atrium. In front of its atrial orifice is a semilunar valve, termed the valve of the inferior vena cava: this is rudimentary in the adult, but is of large size and exercises an important function in the fetus (see page 540).|
Relations.The abdominal portion of the inferior vena cava is in relation in front, from below upward, with the right common iliac artery, the mesentery, the right internal spermatic artery, the inferior part of the duodenum, the pancreas, the common bile duct, the portal vein, and the posterior surface of the liver; the last partly overlaps and occasionally completely surrounds it; behind, with the vertebral column, the right Psoas major, the right crus of the diaphragm, the right inferior phrenic, suprarenal, renal and lumbar arteries, right sympathetic trunk and right celiac ganglion, and the medial part of the right suprarenal gland; on the right side, with the right kidney and ureter; on the left side, with the aorta, right crus of the diaphragm, and the caudate lobe of the liver.
| The thoracic portion is only about 2.5 cm. in length, and is situated partly inside and partly outside the pericardial sac. The extrapericardial part is separated from the right pleura and lung by a fibrous band, named the right phrenicopericardiac ligament. This ligament, often feebly marked, is attached below to the margin of the vena-caval opening in the diaphragm, and above to the pericardium in front of and behind the root of the right lung. The intrapericardiac part is very short, and is covered antero-laterally by the serous layer of the pericardium.|
Peculiarities.In Position.This vessel is sometimes placed on the left side of the aorta, as high as the left renal vein, and, after receiving this vein, crosses over to its usual position on the right side; or it may be placed altogether on the left side of the aorta, and in such a case the abdominal and thoracic viscera, together with the great vessels, are all transposed.
| Point of Termination.Occasionally the inferior vena cava joins the azygos vein, which is then of large size. In such cases, the superior vena cava receives the whole of the blood from the body before transmitting it to the right atrium, except the blood from the hepatic veins, which passes directly into the right atrium.|
Tributaries.The inferior vena cava receives the following veins:
|Right Spermatic or Ovarian.||
| The Lumbar Veins (vv. lumbales) four in number on each side, collect the blood by dorsal tributaries from the muscles and integument of the loins, and by abdominal tributaries from the walls of the abdomen, where they communicate with the epigastric veins. At the vertebral column, they receive veins from the vertebral plexuses, and then pass forward, around the sides of the bodies of the vertebræ, beneath the Psoas major, and end in the back part of the inferior cava. The left lumbar veins are longer than the right, and pass behind the aorta. The lumbar veins are connected together by a longitudinal vein which passes in front of the transverse processes of the lumbar vertebræ, and is called the ascending lumbar; it forms the most frequent origin of the corresponding azygos or hemiazygos vein, and serves to connect the common iliac, iliolumbar, and azygos or hemiazygos veins of its own side of the body.|
| The Spermatic Veins (vv. spermaticæ) (Fig. 590) emerge from the back of the testis, and receive tributaries from the epididymis; they unite and form a convoluted plexus, called the pampiniform plexus, which constitutes the greater mass of the spermatic cord; the vessels composing this plexus are very numerous, and ascend along the cord, in front of the ductus deferens. Below the subcutaneous inguinal ring they unite to form three or four veins, which pass along the inguinal canal, and, entering the abdomen through the abdominal inguinal ring, coalesce to form two veins, which ascend on the Psoas major, behind the peritoneum, lying one on either side of the internal spermatic artery. These unite to form a single vein, which opens on the right side into the inferior vena cava, at an acute angle; on the left side into the left renal vein, at a right angle. The spermatic veins