THE ABDOMEN 7^7 



its usaal position on its right side. This may be due to a transposition of 

 viscera, or to a permanent patency of the lower part of the left cardinal vein 

 oi foetal life. (2) The inferior vena cava, in very rare cases, may terminate 

 in a large right azygos vein, and, through means of that, in the superior 

 vena cava. Under these circumstances the hepatic veins open into the right 

 auricle of the heart. 



Development. — The postrenal segment of the inferior vena cava is usually 

 regarded as being developed from the lower portion of the right posterior 

 cardinal vein. The prerenal segment is developed from (i) the upper portion 

 of the right subcardinal vein; (2) the hepatic sinusoids, and (3) the vena 

 hepatica communis (Lewis). 



Aortic Lymphatic Glands. — ^These glands are very numerous, and 

 are arranged in four groups, which lie around the abdominal aorta. 

 The groups are spoken of as pre-aortic, lateral aortic, right and left, 

 and retro-aortic, respectively. 



Pre-aortic Glands. — ^These are usually disposed in three sets, 

 namely, (i) coeliac glands, which constitute a very distinct set 

 around the origin of the coeliac axis; (2) superior mesenteric glands, 

 in the region of the origin of the superior mesenteric artery, and 

 along the trunk of the vessel ; and (3) inferior mesenteric glands, in 

 the region of the origin of the inferior mesenteric artery. 



The afferent vessels of the pre-aortic glands are derived from the 

 following sources : 



1. Rectum. 8. Vermiform appendix. 



2. Pelvic colon. 9. Small intestine. 



3. Iliac colon. lo. Stomach. 



4. Descending colon. 11. Liver. 



5. Transverse colon. 12. Pancreas. 



6. Ascending colon. 13. Spleen. 



7. Caeciun. 14. Lateral aortic glands. 

 The coeliac glands, more particularly, receive their chief afferent 



vessels from the following glands : 



1. Coronar}^ or gastric glands. 3. Hepatic glands. 



2. Retro-pyloric glands. 4. Splenic glands. 



5. Pancreatic glands. 



The efferent vessels of the pre-aortic glands usually unite to form 

 one trunk, called the intestinal lymphatic trunk, which opens into 

 the receptaculum chyli, a few of them having traversed the retro- 

 aortic glands. 



Lateral Aortic Glands (Lateral Lumbar Glands). — ^These are dis- 

 posed in two groups — right and left. The right lateral aortic glands 

 lie both in front of, and behind, the inferior vena cava ; whilst the 

 glands of the left side form a single chain on the left side of the 

 abdominal aorta. 



The lateral aortic glands, of either side, receive their afferent 

 vessels from the following sources : 



1. Common iliac glands. 4. Ovar>% Fallopian tube, and ad- 



2. Limibar (lateral limibar) jacent half of body of uterus. 



glands. 5. Suprarenal body. 



3. Testis. 6. Kidney. 



