THE ABDOMINAL WALL 229 



the extra-peritoneal fat between the peritoneum and the fascia 

 transversalis ; then, having pierced that fascia, it is situated 

 between the fascia and the posterior surface of the rectus; 

 finally, having passed in front of the linea semicircularis, it lies 

 between the rectus and the posterior wall of the sheath of 

 that muscle. In addition to the relations mentioned it has 

 others of equal importance, viz., (i) as it runs upwards it lies 

 close to the medial side of the abdominal inguinal ring; (2) 

 as the spermatic cord traverses the commencement of the 

 inguinal canal it lies in front of the artery, separated from it 

 only by transversalis fascia ; (3) as the ductus deferens, or the 

 round ligament of the uterus, passes from the inguinal canal 

 into the abdominal cavity it hooks round the lateral side of 

 the artery. 



The branches which spring from the inferior epigastric are 



eternal spermatic. 3. Muscular. 



*', , Ai, 4 ' CUt 



The external spermatic is a small twig which supplies the 

 cremaster muscle and anastomoses with the internal spermatic 

 artery. The/z/^/V, also insignificant in size, runs medially on 

 the pubis, and sends downwards an obturator branch which 

 anastomoses with a small branch from the obturator artery. 

 The importance of the pubic branch arises from the fact that 

 the anastomosis which it establishes sometimes becomes so 

 large as to take the place of the obturator artery. The 

 muscular branches are given to the substance of the rectus, 

 and the cutaneous offsets pierce the abdominal muscles and 

 anastomose with the superficial epigastric artery. The 

 anastomotic branches pierce the posterior lamella of the 

 internal oblique aponeurosis and anastomose, between the 

 transversus abdominis and the internal oblique muscles, with 

 the lower intercostal, the subcostal, and the lumbar arteries. 



Arteria Circumflexa Ilium Profunda. The deep circum- 

 flex iliac artery springs from the lateral side of the external iliac 

 artery, about the same level as the inferior epigastric, and runs 

 laterally, behind the inguinal ligament, to the anterior superior 

 spine of the ilium. From that point onwards it takes the 

 crest of the ilium as its guide, and it ends by anastomosing 

 with branches of the ilio-lumbar artery. At first it is placed 

 in the extra-peritoneal fat, between the fascia transversalis and 

 the peritoneum. Its course behind the inguinal ligament is 

 ii 15 & 



