DISSECTION OF THE LOWER EXTREMITY 145 



below Poupart's ligament to within two or two and a half cen- 

 timetres of the spina iliaca anterior superior, so as to sever the 

 attachment of this portion of the fascia lata from the ligament. 

 Reflect the fascia and margo falciformis downward and lateral- 

 ward. Carefully pick out the fat and deep subinguinal lymph- 

 glands immediately subjacent, so as to expose the connective 

 tissue sheath of the femoral vessels. With the handle of the 

 scalpel gently separate the sheath from Poupart's ligament in 

 front and from Gimbernat's ligament medialward from it. 



What is the shape of the femoral sheath? Note the points 

 where it is perforated by 



(a) Lumbo-inguinal branch of genitofemoral nerve. 



(b) Large saphenous vein. 



(c) Lymp h- vessels. 



By a study of the cadaver, the use of models and a systematic 

 text-book of anatomy, ascertain how it is that the anterior wall 

 of the femoral sheath represents the continuation into the thigh 

 of the fascia transversalis of the abdomen, the posterior wall of 

 the sheath the continuation of the fascia iliaca of the abdomen. 



Next open the femoral sheath by making three parallel and 

 vertical incisions, the first over the femoral artery, the second 

 over the femoral vein, and the third one centimetre medial 

 from the second. The incisions all begin above at the Lig. in- 

 guinale [Pouparti], the medial one being one centimetre long, 

 each of the other two from three to four centimetres long. Note 

 the septa, dividing the sheath into three compartments (Fig. 

 58)- 



(a) Lateral compartment. 



It contains the A. femoralis and the N. lumbo-inguinalis. 



(b) Middle compartment. 



It contains the V. femoralis. 



(c) Medial compartment (femoral canal or canalis femoralis) (0. T. 



crural canal). 



It contains a lymph-gland ( Rosenmiiller's lymph-gland), some 

 lymphatic vessels, and loose areolar tissue. 



Observe that the femoral sheath and its contents completely 

 fill up the lacuna vasorum. How is the lacuna vasorum bounded ? 

 How is the lacuna musculorum bounded? What structures pass 

 through the lacuna musculorum? This latter region will be dis- 

 sected later. 



Introduce the little finger into the canalis femoralis. 

 long is it ? How is it bounded ? Locate exact position of superior 



10 



