394 CLINICAL APPLIED ANATOMY. 



the interior is exposed that the smooth aspect of the peritoneum 

 is seen. 



The somewhat rare form of direct inguinal hernia is one in 

 which the protrusion takes place within Hesselbach's triangle, 

 the boundaries of which are, externally, the deep epigastric 

 artery ; internally, the outer border of the rectus abdominis ; 

 and, below, the inner half of Poupart's ligament. It is difficult or 

 well-nigh impossible to diagnose without dissection the difference 

 between an indirect (or oblique) and a direct inguinal hernia. 

 If the finger can be introduced into the inguinal canal and the 

 pulsation of the deep epigastric artery felt, the protrusion of the 

 hernia, on the patient coughing, internal to this artery proves 

 its direct course. It is important to remember that in a con- 

 siderable proportion of large, indirect, inguinal hernise the neck 

 of the sac drags the deep epigastric artery downwards and 

 inwards, till at last the deep and the superficial rings are almost 

 directly the one behind the other, the hernia in such a case 

 simulating a direct one very closely. 



Femoral Hernia. Behind the innermost part of Poupart's 

 ligament and a little below and external to the spine of the 

 os pubis is a potential opening, made patent by the scalpel or 

 by the protrusion of a femoral hernia. This is the so-called 

 "femoral ring." and is the upper or abdominal entrance into 

 the femoral canal. It has an oval shape, with the long axis 

 transversely placed, and in the erect position its plane is nearly 

 horizontal. 



Its boundaries are, internally, Gimbernat's ligament, which is 

 in reality the triangular internal attachment of Poupart's liga- 

 ment ; externally, the common femoral vein, separated by the 

 septum of the femoral sheath ; in front is Poupart's ligament 

 itself ; and behind is the pectineus muscle covered by the 

 pectineus fascia, while deep to the muscle is the horizontal 

 ramus of the os pubis. 



The femoral ring opens into the femoral canal, which is the 

 most internal division of the femoral sheath, and is composed 

 anteriorly, of the transversalis fascia, and, posteriorly, of iliac 



