228 ABDOMEN 



In the female the inguinal canal is much smaller than in 

 the male. It has the same boundaries ; and it is traversed 

 by the round ligament of the uterus. 



Arteries of the Abdominal Wall. The following arteries 

 will be found in the abdominal wall : 



1. Intercostal and lumbar arteries. 



2. The inferior epigastric artery. 



3. The deep circumflex iliac artery. 



4. The superior epigastric artery. 



5. The musculo-phrenic artery. 



The intercostal arteries of the lower two spaces are pro- 

 longed forwards between the internal oblique and the trans- 

 versus abdominis. They have already been noted accom- 

 panying the corresponding nerves. In front, they anastomose 

 with branches of the epigastric arteries, whilst, inferiorly, they 

 effect communications with the lumbar arteries. 



The main stems of the lumbar arteries ramify between 

 the same two muscles as the preceding vessels, but at a lower 

 level in the abdominal wall. Anteriorly, they anastomose with 

 branches of the inferior epigastric artery; above, with the 

 intercostal arteries ; and below, with the deep circumflex iliac 

 and the ilio-lumbar arteries. 



Arteria Epigastrica Inferior (O.T. Deep Epigastric Artery). 

 The inferior epigastric branch of the external iliac artery is 

 a vessel of some size. It takes origin about a quarter of an 

 inch above the inguinal ligament. At present it is seen 

 shining through the fascia transversalis and forming the lateral 

 boundary of Hesselbach's triangle. Divide the fascia trans- 

 versalis along its course and note the two veins which accom- 

 pany the artery ; then study the course and relations of the 

 vessel. At first it runs medially for a short distance, between 

 the inguinal ligament and the abdominal inguinal ring, and 

 then, changing its direction, it is carried upwards and medially 

 on the medial side of the ring towards the lateral border of 

 the rectus abdominis. Continuing upward behind the rectus 

 abdominis it pierces the transversalis fascia, then, passing in 

 front of the linea semicircularis, it enters the sheath of the 

 rectus, in which it ascends vertically, and it terminates, at the 

 level of the lower margin of thorax, in branches which enter 

 the substance of the rectus, where they anastomose with the 

 ramifications of the superior epigastric artery. 



In the lower parts of its course the artery is embedded in 



