576 DISSECTION OF THE THIGH. 



that bone ; and then brings the movable femur towards the middle line 

 with the other adductors. 



Supposing the foot resting on the ground the gracilis will aid in propping 

 the pelvis on the limb. 



The PECTINEUS (fig. 196, p ) is the highest of the muscles directed from 

 the pelvis to the inner side of the femur. It has a fleshy origin from the 

 ilio-pectineal line of the hip bone, and from the triangular smooth surface 

 in front of that line; and it is inserted inferiorly by a tendon, about two 

 inches in width, into the femur behind the small trochanter, and into the 

 upper part of the line which extends from that process to the linea aspera. 

 The muscle is twisted, so that the surfaces which are directed forwards 

 and backwards near the pelvis are turned inwards and outwards at the 

 femur. One surface is in contact with the fascia lata; and the opposite 

 touches the obturator muscle and nerve, and the adductor brevis. The 

 pectineus lies between the psoas and the adductor longus ; and the internal 

 circumflex vessels pass between its outer border and the psoas. 



Action. It adducts the limb and bends the hip-joint. When the femur 

 is fixed it can support the pelvis in standing; or it can draw forwards the 

 pelvis in stooping. 



The ADDUCTOR LONGUS lies below the pectineus (fig. 196, G ), and is 

 triangular in form, with the apex at the pelvis and the base at the femur. 

 It arises by a narrow tendon from the front of the pubes below the angle 

 of union of the crest and the symphysis ; and it is inserted into the inner 

 edge of the linea aspera. 



This muscle is situate between the gracilis and the pectineus, and forms 

 part of Scarpa's triangular space. Its anterior surface is covered near the 

 femur by the femoral vessels and the sartorius : the posterior rests on the 

 other two adductors, on part of the obturator nerve, and on the deep 

 femoral artery. Aponeurotic bands connect the tendon of insertion with 

 the adductor magnus and vastus internus. 



Action. With the femur movable, it will flex the hip-joint, and with 

 the aid of the other adductors will carry inwards the limb, so as to cross 

 the thigh bones. In walking it helps the other adductors to project the 

 limb. 



With the femur fixed, the muscle props and tilts forwards the pelvis. 

 Dissection. The adductor brevis muscle, with the obturator nerve and 

 the profunda vessels, will be arrived at by reflecting the two last muscles. 

 On cutting through the pectineus near the pubes, and throwing it down, 

 the dissector may find occasionally the small accessory nerve of the obtu- 

 rator which turns beneath the outer border; if this is present, its branches 

 to the hip joint and the obturator nerve are to be traced out. The adductor 

 longus is then to be divided near its origin, and raised with care, so as not 

 to destroy the branches of the obturator nerve beneath ; its tendon is to 

 be detached from that of the adductor magnus beneath it, to see the 

 branches of the profunda artery. 



Now the adductor brevis will be laid bare. A part of the obturator 

 nerve crosses over this muscle to the femoral artery, and sends an offset 

 to the plexus at the inner side of the thigh: a deeper part of the same 

 nerve lies beneath this adductor. The muscle should be separated from 

 the subjacent adductor magnus, where the lower branch of the nerve with 

 an artery issues. In this last ste t > of the dissection the student should 

 trace on and in the fibres of the adductor magnus a slender articular 

 branch of the obturator nerve to the knee. 



