158 



ATLAS AND TEXT-BOOK OF HUMAN ANATOMY. 



Fig. 247. — The superficial layer of the abdominal muscles and the serratus anterior seen from the left 



side. 

 The pectoralis major and minor and the inner portion of the clavicle have been removed and the arm has been 

 drawn backward. 



iliac crest opposite to the glutaeus medius. In the region of the symphysis pubis the tendinous 

 fibers of the aponeurosis form an opening by bridging over the space between the pubic spine 

 (the insertion of the inguinal ligament) and the upper margin of the symphysis. In this manner 



Obliquus abdominis externus 

 Muscle surface Aponeurosis 



Linea alba 



Intcrcrural fib 



Anterior superior 

 spine of ilium 



Inguinal ligament 



Superior y 



Xiz- ^jirnT x-3^ ,i • -Mr 3 W !>*§£•-* / Acetabulum 



Subcutaneous ingui 



ring 



Inferior pillar ( 

 ligamcn 



Reflected 

 inguinal 



''£• Symphysis pubis 



Fig. 246. — Diagram of the subcutaneous inguinal ring. On the right only a portion of the aponeurosis of the obliquus 



abdominis is represented. 



there is formed a triangle, the outer angle of which is directed upward and outward, and which 

 constitutes the subcutaneous inguinal (external abdominal) ring (Figs. 245 and 246). The 

 margins of the ring are formed by the aponeurosis of the obliquus abdominis externus, and 

 are known as the superior cms or pillar and the inferior cms or pillar of the ring. 



The upper and outer angle of this triangular slit in the aponeurosis of the external oblique 

 muscle is rounded off by fibers which arise from the region of the inguinal ligament and are 



