372 ANATOMY AND PHYSIOLOGY 



occupy the whole of the space in their sheath. It is on the medial 

 side of the vein, bounded medially by Gimbernat's ligament (which 

 is at the medial extremity of the inguinal ligament) and closed by 

 transversalis fascia only, which at this spot is called the crural 

 septum (septum crurale). 



The femoral canal extends downward from this ring about 

 three-quarters of an inch in the sheath of the femoral vessels. 



HERNIA 



Hernia is denned as a tumor formed by the protrusion of con- 

 tents of a cavity through its wall. This may occur at any weak 

 place in the wall, but is most frequent in the region of the inguinal 

 or femoral canals. 



If any structure slips accidentally through the inguinal canal it 

 forms an inguinal hernia, which most commonly contains a loop 

 of bowel. To replace the bowel or other structure is to reduce the 

 hernia. If the loop cannot be replaced, the hernia is irreducible; 

 and should it become so distended as to interfere with the circula- 

 tion, it is strangulated. 



In direct inguinal hernia the contents of the tumor have passed 

 directly through the conjoined tendon and subcutaneous ring. In 

 indirect inguinal hernia the contents of the tumor have passed 

 through the whole length of the inguinal canal that is, first the 

 abdominal ring, then the canal, then the subcutaneous ring. 



Umbilical hernia occurs at the umbilicus; ventral hernia at 

 any other part of the abdominal wall, except one or both rings. 



Diaphragmatic hernia occurs at a weak or defective point in 

 the diaphragm where an abdominal structure may press its way 

 into the thorax. 



In femoral hernia the bowel or other structure passes through 

 the femoral ring into the femoral canal and pushes its way through 

 the femoral sheath at the oval fossa, or saphenous opening. 



Femoral hernia is more common in women inguinal hernia 

 in men. 



THE EXTREMITIES COMPARED 



Both extremities are servants of the head and trunk. The 

 lower, being fashioned for bearing weight and also for walking or 

 running, are organs of locomotion, transporting the body from 

 place to place as necessity or convenience may dictate; while the 



