230 THE INFERIOR EXTREMITY 



superficial external pudendal and superficial epigastric arteries, 

 and by the efferent lymph vessels from the subinguinal glands 

 on their way to join the deeper subinguinal glands, which 

 lie in the femoral sheath. 



Vena Saphena Magna (O.T. Internal Saphenous Vein). 

 The great saphenous vein is the largest superficial vein of the 

 inferior extremity. It commences on the dorsum of the foot, 

 passes anterior to the medial malleolus and ascends through 

 the leg across the medial surface of the distal third of the 

 tibia, and then along the medial margin of the tibia. It 

 enters the area of dissection at present under consideration 

 at the level of the tuberosity of the tibia, ascends in the 

 posterior part of the medial genicular region, then, inclining 

 forwards and laterally, it passes upwards to the fossa ovalis, 

 where it pierces the fascia cribrosa and the femoral sheath, 

 and terminates in the femoral vein. In its course through 

 the thigh it communicates through the deep fascia with 

 the deep veins, and it receives the following tributaries : ( i ) 

 The lateral femoral circumflex vein^ from the anterior and 

 lateral parts of the thigh. (2) The medial femoral circumflex 

 vein, which commences at the back of the knee where it 

 frequently communicates with the small saphenous vein. The 

 medial femoral circumflex vein runs upwards, curves round 

 the medial side of the thigh and joins the great saphenous 

 vein mid-way between the hip and the knee. (3) The external 

 superficial pudendal vein. (4) The superficial epigastric 

 vein ; and (5) the superficial circumflex vein. The last three 

 tributaries join the great saphenous vein immediately before 

 it passes through the fossa ovalis. There are several valves 

 in the interior of the great saphenous vein which help to 

 divide the column of blood into sections, and so reduce the 

 pressure on the walls of the distal part of the vein. 



Nervi Gutanei. The cutaneous nerves met with in the 

 area of the present dissection are : 



( Ilio-inguinal nerve. 

 From the lumbar plexus, j Lumbo-inguinal nerve. 



(_ Lateral cutaneous nerve of the thigh. 



( Intermediate cutaneous nerve of the thigh. 

 From the femoral nerve, -I Medial cutaneous nerve of the thigh. 



( Saphenous nerve. 



They have already been found and cleaned. Now their 

 positions and distributions should be more fully studied. 



