MUSCLES OK THE ANTERIOE ASPECT OF THE THIGH. 405 



adductor muscles, and forms the sheaths for the sartorius and gracilis muscles. In 

 the middle third of the thigh the fascia under the sartorius is greatly thickened by 

 transverse fibres and binds together the vastus medialis and adductor longus and 

 adductor inagnus muscles. This layer of fascia roofs over the femoral vessels in 

 their course through adductor canal (Hunter's). 



The fascia lata of the buttock is thick anteriorly where it covers and gives 

 origin to the glutssus medius, thinner posteriorly over the glutseus maximus, at 

 the upper border of which it splits to enclose the muscle. It is thickened over 

 the greater trochanter, where it forms the insertion of the greater part of the 

 latter muscle. 



On the posterior surface of the thigh and over the popliteal fossa the fascia is 

 strengthened by transverse fibres derived from the hamstring muscles. The 

 popliteal fascia forming the roof of the popliteal fossa is specially thick, and is 

 usually pierced by the small saphenous vein. 



Femoral Sheath. This is a conical membranous investment, derived from 

 the fascial lining of the abdominal cavity, the fascia transversalis in front and the 

 fascia iliaca behind, prolonged along the femoral vessels in their passage behind 

 the inguinal ligament into the femoral triangle. The sheath is about an inch and 

 a half in length, and is divided into three compartments a lateral space for the 

 artery, an intermediate space for the vein, and a medial channel containing lymph 

 vessels and fat, and named the femoral canal. This canal is the passage through 

 which a femoral hernia enters the thigh. Its proximal limit is the femoral ring, 

 bounded anteriorly by the inguinal ligament, posteriorly by the origin of the 

 pectineus muscle from the pubis, medially by the ligamentum lacunare (Gimbernati)> 

 and laterally by the femoral vein. In front of it the fascia transversalis 

 forming the sheath is thickened to form the deep femoral arch. The part of 

 the inguinal ligament in front of the ring is called the superficial femoral arch. 

 The inferior epigastric artery separates the ring from the abdominal inguinal 

 ring. The canal ordinarily contains fat which is continuous above with the 

 extra -peritoneal tissue. The ring is filled by a plug of fat or a lymph gland, 

 constituting the femoral septum. 



The femoral canal ends behind the fossa ovalis, covered by the fascia cribrosa, 

 while the falciform margin crosses over it and conceals its proximal portion. 

 The course of a femoral hernia is determined by this band. The hernia descends 

 through the femoral ring, pushing the femoral septum before it ; after passing through 

 the femoral canal, it is directed forwards through the fossa ovalis. The anterior 

 part of the hernia being pressed upon and retarded by the femoral arches, and by 

 the falciform margin, the posterior part pushes onwards, hooks round the falciform 

 margin, and is directed upwards over the inguinal ligament. The coverings of a 

 femoral hernia, in addition to peritoneum and extra-peritoneal tissue (femoral 

 septum), are femoral sheath, fascia cribrosa, superficial faspia, and skin. 



MUSCLES OF THE THIGH AND BUTTOCK. 



The muscles of the thigh and buttock are divisible into four main groups by 

 their situation, action, and nerve-supply. On the anterior surface of the thigh are 

 the quadriceps femoris, the sartorius, ilio-psoas, and pectineus muscles ; on the 

 medial side of the thigh are the adductor muscles; in the region of the buttock 

 are the glutaei and rotators of the hip-joint ; and on the posterior aspect of the 

 thigh are the hamstring muscles. 



THE MUSCLES ON THE ANTERIOR ASPECT OF THE THIGH. 



The chief muscle on the anterior aspect of the thigh is the quadriceps femoris, 

 which occupies the space between the tensor fascise latae and ilio-tibial tract 

 laterally, and the sartorius medially. The sartorius crosses the thigh obliquely ; 

 it separates the quadriceps femoris from the adductor muscles ; it forms in the 

 proximal third of the thigh the lateral boundary of the femoral triangle, and in 



