GLUTEAL REGION. 229 



adductors, forms the bulk of the upper part of the thigh, 

 and separates the muscles of the anterior and posterior 

 femoral regions; superiorly it lies beneath the adductor 

 brevis, which should consequently be removed. It aris.es 

 from the rami of the pubes and ischium, and from the 

 tuberosity of the ischium, and is inserted into the inter- 

 trochanteric line, and the whole length of the linea aspera, 

 as far as the inner condyle, where it terminates in a 

 rounded tendon. At its lower part it becomes confounded 

 with the adductor longus and the vastus interims muscles, 

 its upper part it is pierced by the perforating arteries, 

 id lower down it has a large, oval, and tendinous open- 

 ig, converted into a canal by the tendon of the vastus 

 iternus muscle, called Hunter's canal, and through which 

 >s the femoral vessels. 



By detaching the origin of the adductor magnus, the obturator ex- 

 jrnus muscle will be exposed. 



The OBTURATOR EXTERNUS MUSCLE arises from the rami 

 )f the pubes and ischium, and from a part of the surface 

 )f the obturator membrane ; it forms a triangular belly, 

 id its fibres converge to a rounded tendon, which is in- 

 jrted into the digital fossa of the great trochanter. 

 The obturator artery (p. 208), after emerging from the 

 ilvis, divides into two branches, one of which forms a 

 jircle around the membrane beneath the obturator muscle, 

 md sends an articular twig, through the notch of the 

 itabulum, to the head of the femur, which it reaches by 

 leans of the round ligament ; the other branch supplies 

 the obturator and adductor muscles, and unites with the 

 iternal circumflex artery. 



DISSECTION IX. 



GLUTEAL REGION. 



The subject should be turned over, and a high block placed beneath 

 the thighs, in such a way that the pelvis may hang over its edge, and 

 yet remain fixed firmly enough for dissection ; the thigh should be 

 rotated inward, and the foot should lie upon its outer side. An 

 incision is to be made obliquely outward from the upper part of the 

 sacrum, to a point a hand's breadth below the greater trochanter ; this 

 should penetrate to the muscle, and the flaps be reflected by dissect- 

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