THE LOWER LIMB 471 



Nerve-supply. — The anterior or superficial division of the obturator 

 nerve. 



Action. — The muscle is an adductor of the thigh, and a flexor of 

 the knee-joint. Having flexed the knee-joint, it acts as an internal 

 rotator of the leg. 



The gracilis is flat and strap-like in the upper third of the thigh. 

 In the middle third it becomes thick and narrow, and it graduzdly 

 tapers into a long, narrow, round tendon which expands towards 

 its insertion. The surfaces are directed inwards and outwards, the 

 borders looking forwards and backwards. In the lower third of 

 the thigh the tendon has the sartorius in front of it, and the semi- 

 tendinosus behind it, and it is separated from the internal lateral 

 hgament of the knee-joint by a bursa. 



Adductor Longus— -Ori'gm. — ^The upper and inner part of the 

 anterior or femoral surface of the body of the os pubis, immediately 

 below and external to the pubic angle. 



Insertion. — ^The inner hp of the hnea aspera of the femur. 



Nerve-supply. — The anterior or superficial division of the obturator 

 nerve. 



Action. — The muscle is an adductor and external rotator of the 

 thigh, and a flexor of the hip- joint. 



The adductor longus is a flat, triangular muscle, the direction of 

 which is doNvnwardSj outwards, and backwards. It hes to the inner 

 side of the pectineus, and rests upon the adductor brevis, the 

 anterior or superficial diWsion of the obturator nerve, and the 

 adductor magnus. The superficial femoral artery is superficial to 

 it, and the arteria profunda femoris beneath it. 



Adductor Brevis — Origin. — (i) The anterior or femoral surface of 

 the body of the os pubis for rather less than its lower half, immedi- 

 ately external to the gracflis ; and (2) the front of the descending 

 pubic ramus, where it is likewise external to the gracihs. 



Insertion. — The line leading from the back of the small trochanter 

 to the inner lip of the Unea aspera. 



Nerve-supply. — The anterior or superficial division of the obturator 

 nerve (occasionally the posterior division). 



Action. — The muscle is an adductor and external rotator of the 

 thigh, and a flexor of the hip- joint. 



The adductor brevis is quadrilateral, and is directed downwards, 

 outwards, and backwards. It hes behind the pectineus and ad- 

 ductor longus, and upon the adductor magnus. The anterior or 

 superficial division of the obturator nerve is in front of it, 

 and the posterior or deep division behind it. It is pierced by 

 the first two perforating branches of the arteria profunda 

 femoris. 



Adductor Magnus — Origin. — (i) The anterior or femoral surface 

 of the body of the os pubis in its lower fourth, betvs'een the adductor 

 brevis internally and the obturator extemus externally ; (2) the 

 front of the ischio-pubic ramus ; and (3) the inferior portion of the 

 postero-inferior surface of the tuber ischiL 



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