MUSCULAR SYSTEM. 155 



Relations. — Posteriorly and externally, with the faschia and 

 skin ; internally, with the biceps abductor and heads of the 

 gastrocnemii ; anteriorly, with the gracilis. 



Direction. — Longitudinal ; inclining forwards in a curve. 



Structure. — Entirely fleshy, with the exception of the ex- 

 tremities. The upper extremity is prolonged as high as the 

 sacrum by means of aponeurosis, which forms part of the 

 faschia lata. The inferior extremity is affixed to the condyle 

 by a strong flattened tendon. 



Action. — That of the three adductors is to extend the os femoris 

 upon the pelvis; so that they are opponents to the psoas 

 magnus and iliac us, which flex the haunch : they are also pow- 

 erful adductors of the whole limb. The great adductor will, 

 moreover, assist in bending the thigh, and will rotate it inwards 

 a little. 



5— POSTERIOR ILIO-FEMORAL REGION. , 



The muscles of this region occupy the outer and posterior side 

 of the haunch. 



BICEPS ABDUCTOR FEMORIS. — Ischio-tibialis Medius ve\ 

 Posterior. 



Situation. — Postero-external side of the haunch and thigh ; 

 where, being superficial, its course is well marked in the living- 

 animal. 



Attachment. — Superiorly, to the lateral and posterior parts of 

 the spine of the sacrum, and some of the upper pieces of the 

 OS coccygis ; to the sacro-sciatic ligaments; to the tuberosity of 

 the ischium, and to the faschia lata. Inferiorly, it is split into 

 two portions, one of which is attached to the patella and its 

 external ligament; the other (through the intervention of an 

 aponeurotic expansion) to the ridge upon the upper part of the 

 tibia, and to the faschia covering the leg. 



Relations. — Externally, with the faschia and skin ; internally 

 and superiorly, with the gluteus maximus ; internally and inferi- 

 orly, with the gastrocnemii; anteriorly, with the external tro- 

 chanters, major and minor, and with the body of the femoral 

 bone ; posteriorly, with the tuberosity of the ischium and serai- 

 tendinosus. 



Structure. — Fleshy ; surfaces, aponeurotic. Attached by a 

 broad flat tendon to the tuberosity of the ischium ; by a more 

 slender one, to the trochanter minor externus ; by a broad, flat- 

 tened, and thick tendon, invested by some few fleshy fibres, to 

 the patella and its ligament ; and to the tibia and tibial faschia 



