416 ABDOMINAL AOHTA. 



In the female, the ovarian arteries, corresponding to the spermatic arteries 

 in the male, are shorter than these vessels, and do not pass out of the abdo- 

 minal cavity. The origin, direction, aud connections of the ovarian artery 

 in the first part of its course are the same as in the male ; but at the 

 margin of the pelvis it inclines inwards, and running tortuously between 

 the layers of the broad ligament of the uterus, is guided to the attached 

 margin of the ovary, which it supplies wish branches. Some small offsets 

 can be also traced along the round ligament into the inguinal canal, and 

 others along the Fallopian tube : one, continuing inwards towards the 

 uterus, joins with the uterine artery. 



In the young foetus the spermatic and ovarian arteries are short, as the testes and 

 the ovaries are at first placed close to the kidneys, but the arteries become lengthened 

 as these organs descend to their ultimate positions. 



PECULIARITIES. The spermatic arteries occasionally arise by a common trunk. 

 Two spermatic arteries are not unfrequently met with on one side ; both of these 

 usually arise from the aorta, though sometimes one is a branch from the renal artery. 

 A case has occurred of three arteries on. one side, two from the aorta and the third 

 from the renal. 



B. PARIETAL BRANCHES OF THE ABDOMINAL AORTA. 



I. INFERIOR PHRENIC ARTERIES. 



The phrenic arteries are two small vessels, which spring from the aorta 

 close together on a level with the under surface of the diaphragm. These 

 arteries are, however, somewhat irregular in their orgin. When they arise 

 separately from each other, which is by no means a constant arrangement, 

 one is frequently derived from the cceliac artery close to the origin, aud the 

 other from the aorta immediately above. They soon diverge from each 

 other, and, passing across the crura of the diaphragm, incline upwards aud 

 outwards upon its under surface ; the artery of the left side passing behind 

 the oesophagus, whilst that of the right side passes behind the vena cava. 

 Before reaching the central tendon of the diaphragm, each of the arteries 

 divides into two branches, of which one runs forwards towards the anterior 

 margin of the thorax, and anastomoses with the mu-sculo-phrenic branch of 

 the internal mammary artery, while the other pursues a transverse direction 

 towards the side of the thorax, and communicates with the terminations of 

 the intercostal arteries. 



BRANCHES. Each phrenic artery gives small branches (superior capsular) to the 

 suprarenal capsule of its own side ; the left artery sends some branches to the 

 oesophagus, whilst the artery of the right side gives off small vessels which reach the 

 termination of the vena cava. Small offsets descend to the liver between the layers 

 of the peritoneum. 



PECULIARITIES. The phrenic arteries are found to vary greatly in their mode of 

 origin, but these deviations seem to have little influence on their course and dis- 

 tribution. In the first place they may arise either separately, or by a common trunk : 

 and it would appear that the latter mode of origin is nearly as frequent as the 

 former. 



When the two arteries are joined at their origin, the common trunk arises most 

 frequently from the aorta ; though, sometimes, it springs from the coeliac axis. 



When arising separately, the phrenic arteries are given off sometimes from the* 

 aorta, more frequently from the coeliac axis, and occasionally from the renal ; but it 

 most commonly happens that the artery of the right side is derived from one, and 

 that of the left side from another of these sources. An additional phrenic artery 

 (derived from the left hepatic) has been met with. 



. 



