612 ANGIOLOGY 



spermatic, but on arriving at the upper opening of the lesser pelvis the ovarian 

 artery passes inward, between the two layers of the ovariopelvic ligament and of 

 the broad ligament of the uterus, to be distributed to the ovary. Small branches 

 are given to the ureter and the uterine tube, and one passes on to the side of the 

 uterus, and unites with the uterine artery. Other offsets are continued on the round 

 ligament of the uterus, through the inguinal canal, to the integument of the labium 

 ma jus and groin. 



At an early period of fetal life, when the testes or ovaries lie by the side of the 

 vertebral column, below the kidneys, the internal spermatic or ovarian arteries 

 are short; but with the descent of these organs into the scrotum or lesser pelvis, 

 the arteries are gradually lengthened. 



The inferior phrenic arteries (aa. phrenicce inferiores) (Fig. 531) are two small 

 vessels, which supply the diaphragm but present much variety in their origin. 

 They may arise separately from the front of the aorta, immediately above the celiac 

 artery, or by a common trunk, which may spring either from the aorta or from the 

 celiac artery. Sometimes one is derived from the aorta, and the other from one of 

 the renal arteries; they rarely arise as separate vessels from the aorta. They 

 diverge from one another across the crura of the diaphragm, and then run ob- 

 liquely upward and lateralward upon its under surface. The left phrenic passes 

 behind the esophagus, and runs forward on the left side of the esophageal hiatus. 

 The right phrenic passes behind the inferior vena cava, and along the right side 

 of the foramen which transmits that vein. Near the back part of the central 

 tendon each vessel divides into a medial and a lateral branch. The medial branch 

 curves forward, and anastomoses with its fellow of the opposite side, and with 

 the musculophrenic and pericardiacophrenic arteries. The lateral branch passes 

 toward the side of the thorax, and anastomoses with the lower intercostal arteries, 

 and with the musculophrenic. The lateral branch of the right phrenic gives off 

 a few vessels to the inferior vena cava; and the left one, some branches to the 

 esophagus. Each vessel gives off superior suprarenal branches to the suprarenal 

 gland of its own side. The spleen and the liver also receive a few twigs from the 

 left and right vessels respectively. 



The lumbar arteries (aa. lumbales] are in series with the intercostals. They 

 are usually four in number on either side, and arise from the back of the aorta, 

 opposite the bodies of the upper four lumbar vertebrae. A fifth pair, small in size, 

 is occasionally present: they arise from the middle sacral artery. They run lateral- 

 ward and backward on the bodies of the lumbar vertebrae, behind the sympathetic 

 trunk, to the intervals between the adjacent transverse processes, and are then 

 continued into the abdominal wall. The arteries of the right side pass behind the 

 inferior vena cava, and the upper two on each side run behind the corresponding 

 crus of the diaphragm. The arteries of both sides pass beneath the tendinous 

 arches which give origin to the Psoas major, and are then continued behind this 

 muscle and the lumbar plexus. They now cross the Quadratus lumborum, the upper 

 three arteries running behind, the last usually in front of the muscle. At the lateral 

 border of the Quadratus lumborum they pierce the posterior aponeurosis of the 

 Transversus abdominis and are carried forward between this muscle and the 

 Obliquus internus. They anastomose vdth the lower intercostal, the subcostal, 

 the iliolumbar, the deep iliac circumflex, and the inferior epigastric arteries. 



Branches. In the interval between the adjacent transverse processes each lumbar 

 artery gives off a posterior ramus which is continued backward between the trans- 

 verse processes and is distributed to the muscles and skin of the back ; it furnishes 

 a spinal branch which enters the vertebral canal and is distributed in a manner 

 similar to the spinal branches of the posterior rami of the intercostal arteries 

 (page 601). Muscular branches are supplied from each lumbar artery and from its 

 posterior ramus to the neighboring muscles. 



