BRANCHES OF THE ABDOMINAL AORTA. 365 



accompanied by the spermatic vein, and the spermatic plexus of 

 nerves. In the fcetus before the testicle lea.ves the abdomen the condition in 

 spermatic artery is very short, but the vessel elongates as the testis the f( 

 is removed from its original position. 



In the female the corresponding artery (ovarian) descends into the in the 

 pL'lvi< to end in the ovary and the uterus. 



The parietal branches of the aorta are the diaphragmatic, lumbar, Branches 

 and middle sacral. abdomen. 



The diaphragmatic arteries (inferior phrenic ; fig. 138, a) are Inferior 

 frequently united together at their origin, or with the coeliac *' 

 axis. They course upwards along the posterior part of the under course of 

 surface of the diaphragm, the left artery passing behind the right" 

 oesophageal opening, and the right behind the vena cava. Each 

 ends in two branches : One (internal) passes, onwards towards the distribu- 

 front of the diaphragm, and anastomoses with its fellow, and with 

 the superior phrenic and musculo-phrenic branches of the internal 

 mammary. The other (external) is larger, and is directed outwards to 

 the side of the muscle, where it communicates with the intercostal 

 arteries. 



Branches. Small offsets to the suprarenal body from the external small 

 division of this artery are named superior capsular. Some twigs are 

 given by the left artery to the oesophagus, and by the right to the 

 vena cava. 



On the under-surface of the diaphragm are two branches of other 

 the internal mammary artery of the thorax, one, superior phrenic, diaphragm, 

 accompanies the phrenic nerve, and ramifies over the middle 

 of the muscle ; the other, musculo-phrenic, appears opposite the 

 ninth' cartilage, and supplies the tipper costal slips of the 

 diaphragm. 



The other parietal branches of the aorta, viz., lumbar and middle 

 sacral, are not learnt in this stage : the former will be examined 

 after the lumbar plexus (p. 374), and the latter in the pelvis (p. 400). 



The COMMON ILIAC ARTERY (fig. 138, g) is directed downwards common 

 and outwards from the bifurcation of the aorta, and divides into iliac artery 

 two large trunks opposite the fibro-cartilage between the last lumbar extent and 

 vertebra and the sacrum ; one of these (external iliac] supplies the 

 lower limb, and the other (internal iliac) enters the pelvis. Placed relations ; 

 obliquely on the vertebral column, the vessel measures about two 

 inches in length. It is covered by the peritoneum, and is crossed 

 by branches of the sympathetic nerve, and sometimes by the ureter. 

 It is accompanied by a vein of the same name. Usually it does usually no 

 not furnish any named branch, but it may give origin to the branches - 

 ilio-lumbar artery. On opposite sides the vessels have some 

 differences. 



The right artery has the vena cava to its outer side above, and Differences 

 near its termination touches the psoas muscle. The companion vein 

 (p) is at first beneath, but becomes external to the artery at the 

 upper part ; and beneath the right artery also is the left common ^^ 

 iliac vein. The left artery is crossed by the superior haernorrhoidal vessel. 



