THE INTERNAL FEMORAL REGION. 425 



aspera, between the Vastus internus and the Adductor magnus, with both of 

 which it is usually blended. 



Relations. By its anterior surface, with the fascia lata, the Sartorius, and, 

 near its insertion, with the femoral artery and vein; by its posterior surface, with 

 the Adductor brevis and magnus, the anterior branches of the obturator nerve, 

 and with the profunda artery and vein near its insertion ; by its outer border, with 

 the Pectineus; by its inner border, with the Gracilis. 



The Pectineus and Adductor longus should now be divided near their origin, and turned 

 downward, when the Adductor brevis and Obturator extcrnus will be exposed. 



The Adductor brevis is situated immediately behind the two preceding muscles. 

 It is somewhat triangular in form, and arises by a narrow origin from the outer 

 surface of the body and descending ramus of the os pubis, between the Gracilis 

 and Obturator externus. Its fibres, passing backward, outward, arid downward, 

 are inserted, by an aponeurosis, into the lower part of the line leading from the 

 lesser trochanter to the linea aspera and the upper part of the same line, imme- 

 diately behind the Pectineus and upper part of the Adductor longus. 



Relations. By its anterior surface, with the Pectineus, Adductor longus, pro- 

 funda femoris artery, and anterior branches of the obturator nerve ; by its pos- 

 terior surface, with the Adductor magnus and posterior branch of the obturator 

 nerve ; by its outer border, with the internal circumflex artery, the Obturator exter- 

 nus, and conjoined tendon of the Psoas and Iliacus ; by its inner border, with the 

 Gracilis and Adductor magnus. This muscle is pierced, near its insertion, by the 

 second or first and second perforating branches of the profunda femoris artery. 



The Adductor brevis should now be cut away near its origin, and turned outward, when 

 the entire extent of the Adductor magnus will be exposed. 



The Adductor magnus is a large triangular muscle forming a septum between 

 the muscles on the inner and those on the back of the thigh. It arises from a 

 small part of the descending ramus of the os pubis, from the ramus of the is- 

 chium, and from the outer margin of the inferior part of the tuberosity 

 of the ischium. Those fibres which arise from the ramus of the os pubis 

 are very short, horizontal in direction, and are inserted into the rough line 

 leading from the great trochanter to the linea aspera, internal to the Gluteus 

 maximus; those from the ramus of the ischium are directed downward and 

 outward with different degrees of obliquity, to be inserted, by means of a broad 

 aponeurosis, into the linea aspera and the upper part of its internal prolonga- 

 tion below. The internal portion of the muscle, consisting principally of those 

 fibres which arise from the tuberosity of the ischium, forms a thick fleshy mass 

 consisting of coarse bundles which descend almost vertically, and terminate about 

 the lower third of the thigh in a rounded tendon, which is inserted into the 

 Adductor tubercle on the inner condyle of the femur, being connected by a fibrous 

 expansion to the line leading upward from the tubercle to the linea aspera. 

 Between the two portions of the muscle an interval is left, tendinous in front, 

 fleshy behind, for the passage of the femoral vessels into the popliteal space. The 

 external portion of the muscle at its attachment to the femur presents three or four 

 osseo-aponeurotic openings, formed by tendinous arches attached to the bone, from 

 which muscular fibres arise. The three superior of these apertures are for the 

 three perforating arteries, and the fourth, when it exists, for the terminal branch 

 of the profunda. 



Relations. By its anterior surface, with the Pectineus, Adductor brevis, 

 Adductor longus, and the femoral and profunda vessels and obturator nerve ; by 

 its posterior surface, with the great sciatic nerve, the Gluteus maximus, Biceps, 

 Semitendinosus, and Semimembranosus. By its superior or shortest border it lies 

 parallel with the Quadratus femoris, the internal circumflex artery passing between 

 them ; by its internal or longest border, with the Gracilis, Sartorius, and fascia 

 lata ; by its external or attached border it is inserted into the femur behind the 

 Adductor brevis and Adductor longus, which separate it from the Vastus internus, 



