420 DISSECTION OF THE ABDOMEN. 



b. A cremasteric branch is furnished to the muscular covering of the 

 cord. 



c. Muscular branches are given from the outer side of the artery to the 

 abdominal wall, which anastomose with the intercostal arteries (p. 419), 

 and others enter the rectus. Cutaneous offsets pierce the muscle, and 

 ramify in the integuments with the anterior cutaneous nerves. 



Two epigastric veins lie with the artery; they join finally into one, 

 which opens into the external iliac vein. 



The circumflex iliac artery arises from the outer side of the external 

 iliac, opposite the epigastric, and courses around the iliac crest, as the 

 name expresses. Having perforated the crural sheath, it passes beneath 

 the transversalis muscle to the middle of the crest of the hip-bone. Here 

 it pierces the transversalis, and is continued backwards between this and 

 the internal oblique, to anastomose with the ilio-lumbar branch of the in- 

 ternal iliac artery. Its otfsets are muscular and anastomotic. 



Branches. Near the front of the iliac crest a small branch ascends be- 

 tween the internal oblique and transversalis muscles, supplying them, and 

 anastomoses with the epigastric and intercostal arteries. 



As the vessel extends backwards it gives lateral offsets, which supply 

 the neighboring muscles, and communicate on the one side with the ilio- 

 lumbar, and on the other with the gluteal artery. 



The circumflex iliac vein is formed by the junction of two collateral 

 branches, and crosses the external iliac artery nearly an inch above Pou- 

 part's ligament, to open into the external iliac vein. 



SECTION II. 



HERNIA OF THE ABDOMEN. 



THE lower part of the abdominal wall, which has been reserved on the 

 left side of the body, should now dissected for inguinal hernia. 



Dissection. The teguments and the aponeurosis of the external oblique 

 having been thrown down in the previous examination of the wall of the 

 abdomen, the necessary dissection of the inguinal region will be completed 

 by raising the internal oblique muscle, as in fig. 140. 



To raise the oblique muscle, let one incision be made across the fleshy 

 fibres from the iliac crest towards the linea alba ; and after the depth of 

 the muscle has been ascertained by the layer of areolar and fatty tissue 

 beneath it, let the lowest fibres be carefully cut through at their attach- 

 ment to Poupart's ligament. By raising the muscle cautiously, the stu- 

 dent will be able to separate it from the subjacent transversalis, so that it 

 may be turned upwards on the abdomen. The separation of the two mus- 

 cles just mentioned is sometimes difficult, in consequence of their fibres 

 being blended together, but a branch of the circumflex iliac artery will 

 mark their intermuscular interval. 



The cremaster muscle is next to be divided along the cord, and to be 

 reflected to the sides. Let the dissector then clean the surface of the 

 transversalis muscle, without displacing its lower arched border; and trace 

 with care the conjoined tendon of it and the internal oblique to show the 



