PARIETES OF THE ABDOMEN. 163 



each side of the median line extends a single long muscle. 

 The abdomen is covered by a fascia and a very variable 

 amount of fat. 



The superficial fascia is continuous with that of the 

 thorax and lower extremity. ]S T o special dissection of it is 

 necessary. It is only important in the inguinal region, 

 where it divides into two Ia3^ers, and, as will hereafter be 

 seen, bears certain relations to the surgical affection called 

 hernia ; these two layers are separated by the superficial 

 epigastric artery and vein, the former being a small branch 

 from the femoral, arising below Pou part's ligament, and 

 passing upward toward the umbilicus. It will be seen that 

 certain fibres of the superficial fascia pass from the pubes 

 to the penis, forming a rounded cord called the ligamentum 

 suspensorium penis. In the groin the fascia attaches itself 

 to Poupart's ligament, and through that becomes blended 

 with the fascia of the thigh ; it covers the spermatic cord, 

 and, accompanying it to the scrotum, there unites with the 

 fascia of the perineum. Between its two layers, and above 

 Poupart's ligament, three or four lymphatic glands will be 

 found ; these receive the lymphatics from the abdomen and 

 genital organs, and their efferent ducts pass in at the 

 saphenons opening of the thigh. 



The OBLIQUUS EXTERNUS MUSCLE is the most superficial 

 of the abdominal muscles ; it is aponeurotic in front and 

 fleshy upon the side ; it arises from the external surface of 

 eight or nine lower ribs by processes called digitations, 

 which are received between similar processes belonging to 

 the serratus magnus and latissimus dorsi. It is inserted into 

 the outer edge of the anterior half of the crest of the ilium 

 and its anterior superior spinous process, into the spine, 

 pectineal line and front of the os pubis, and into the whole 

 length of the linea alba. The portion inserted into the crest 

 of the ilium is fleshy ; the remainder consists of a spread- 

 ing aponeurosis, connected above with the pectoralis major 

 muscle, and along the median line uniting with its fellow 

 of the other side ; the interlacement of their fibres forms 

 what is called the linea alba, in the centre of which is the 

 umbilicus, being the cicatrix of the occluded extremities of 

 the umbilical artery and vein which composed the umbilical 

 cord, divided at the time of birth, and the stump of which 

 subsequently sloughs off. Between the anterior superior 

 spinous process of the ilium and the spine of the pubes 

 the fibres of the external oblique become rolled into a sort 



