452 THE ANATOMY OF THE HORSE 



ANTERIOR ILIO-FEMORAL REGION 



Trifemoro rotul.eus consists of a mass of muscle lying beneath the 

 tensor vaginse, and forming the anterior prominence of the haunch. It 

 consists of three divisions — the rectus, vastus externus, and internus. 

 Rectus femoris is anterior and superior to the other portions. Origin 

 — from the ilium, just above the acetabulum. Insertion — to the anterior 

 part of the capsular ligament and supero-lateral part of the patella. 

 Action — to extend the thigh and draw it under the body. The two 

 vasti consist of a mass of muscle occupying the front and sides of the 

 ftmur, and lying beneath the rectus. Origin — from the whole of the 

 ujper part of the femur to the roots of the trochanters. Insertion — to 

 the upper edge and sides of the patella. Action — to assist the rectus in 

 extending the thigh and lifting the stifle under the body in progression. 



Rectus parvus is an humble imitation of the human crureus, lying 

 deep beneath the rectus femoris on the upper part of the femur. It is a 

 small cylindrical muscle, having its origin from the ilium external to that 

 of the rectus femoris, and its belly lying between the two vasti close 

 upon the bone; it is inserted on the anterior face of the femur. Its 

 action is chiefly to defend the capsular ligament of the iliofemoral 

 articulation. 



INTERNAL ILIO-FEMORAL REGION 



Sartorius lies on the antero-internal part of the haunch. Origin — 

 from the inferior part of the transverse process of the first sacral bone 

 and venter ilii. Insertion — to the inner and inferior part of the lateral 

 ligament of the patella, and through the medium of the gracilis to the 

 supero-internal part of the tibia. Action — to bend the leg and to draw it 

 inwards. 



Gracilis is situated on the internal part of the haunch. Origin — from 

 the anterior and posterior ends of the symphysis pubis. Insertion — to 

 the spinous ridge on the supero-internal part of the tibia. Action — to 

 raise the leg and draw it inwards. 



Pectineus lies close to the sartorius. Origin — from the anterior surface 

 of the OS pubis, near the symph^^sis and acetabulum. Insertion — to the 

 ridge of the femur, leading downwards from the trochanter internus. 

 Action — to flex and adduct the femur. 



Adductor longus lies at the back of the mass of internal muscles of 

 the haunch. Origin from the inferior surface of the ischium, and from 

 the adjacent fascia. Insertion — by two portions, which ar-e distinguished 

 as separate muscles by some anatomists. One (A. magnus) into the pos- 

 terior face of the femur external to the adductor brevis ; the other (A. 

 longus), to the inner and upper part of the internal condyle. Action — to 

 adduct and rotate the femur inwards. 



Adductor brevis lies covered by the adductor magnus. Origin — from 

 the inferior surface of the os pubis. Insertion — to the square rough surface 

 on the posterior face of the femur. Action — to adduct the femur. 



