THE GLUTEAL REGION 



419 



as superior or inferior gluteal 



Plit.^ 



yilfb^ 



piriformis. They are known 

 hernia. The former variety 

 is the less uncommon, and 

 it occurs more often in the 

 female and on the right side 

 of the body. The neck of 

 the sac lies in the fossa 

 ovarica (p. 393) in the angle 

 between the obturator and 

 the hypogastric arteries. 

 If the hernia becomes 

 strangulated, the constric- 

 tion at the neck should be 

 divided in a downward and 

 lateral direction, parallel to 

 the fibres of the piriformis. 



The tendon of the obturator 

 interims (p. 355) leaves the pelvis 

 through the lesser sciatic foramen 

 and passes laterally to the greater 

 trochanter. The superior and 

 inferior gemelli are attached to 

 its upper and lower margins. 

 This tricipital tendon, which 

 abducts the thigh and rotates 

 it laterally, is closely related to 

 the posterior aspect of the cap- 

 sule of the hip-joint. The ob- 

 turator internus is supplied by 

 a special branch from the sacral 

 plexus (L. 5, S. i, 2). 



The quadratus femoris is 

 placed at a slightly lower level. 

 Its fibres are practically horizon- 

 tal and extend from the ischial 

 tuberosity to the quadrate tub- 

 ercle on the intertrochanteric 

 crest (posterior intertrochanteric 

 line), so that the muscle acts as 

 a lateral rotator and also as an 

 adductor. It receives a special 

 branch from the sacral plexus 

 (L. 4, 5, S. i). 



The Hip-Joint is 



formed by the articulation FlG p ^4. -The Cutaneous Nerves on the 



Posterior Aspect of the Lower Limb, 

 of the rounded head of the 



femur with the cup-shaped acetabulum on the lateral aspect 

 of the hip-bone. The ilium, ischium, and pubis all share in 



27 a 



Lumbar nerves 



Cutaneous branches 



of the 1 2th thoracic 



and ilio-hypogastric 



nerves 



Sacral nerves 



Perforating 

 cutaneous 



Branches from 



posterior cutaneous - 



nerve of the thigh 



Lateral cutaneous 



nerve of the thigh 



Long perineal 



Posterior cutaneous 

 nerve of the thigh 



Medial cutaneous 

 nerve of the thigh 



Lateral cutaneous 

 nerve of the thigh 



Medial cutaneous 

 nerve of the thigh 



Anastomotic peroneal 

 nerve 



Posterior cutaneous 

 nerve of the thigh 



Medial cutaneous nerve 

 of the calf (O.T. ramus 

 communicans tibialis) 



Nervus suralis 

 (O.T. short saphenous) 



Medial calcanean branch 





