GLUTEAL REGION 295 



interims; (5) the gemellus inferior, attached to the inferior 

 border of the obturator internus ; (6) the quadratus femoris, 

 attached medially to the ischial tuberosity and laterally to 

 the distal part of the trochanter major, and to the proximal 

 part of the body of the femur; (7) the proximal part of the 

 adductor magnus, immediately distal to the quadratus femoris; 

 (8, 9, and 10) the biceps femoris, the semitendinosus and the 

 semimembranosus (hamstrings), springing from the tuberosity 

 of the ischium. In addition to the above-mentioned muscles 

 the dissector should note (n) that the proximal part of the 

 vastus lateralis is under cover of the tendinous insertion of the 

 glutaeus maximus, distal to the lateral part of the trochanter 

 major, and (12 and 13) that the lower and medial part of 

 the glutaeus maximus, which forms the posterior boundary 

 of the ischio-rectal fossa, is separated by a pad of fat from 

 the levator ani and the coccygeus muscles, which form the 

 medial wall of the fossa. 



The vessels and nerves under cover of the glutaeus maximus 

 are also numerous ; they are : 



(1) Issuing between the adjacent borders of the glutaeus 

 medius and piriformis and passing into the deep surface of 

 the glutaeus maximus, superficial branches of the superior gluteal 

 artery. The trunk from which the branches spring, and the 

 superior gluteal nerve, which accompanies it, can be seen if 

 the borders of the muscles are separated. 



(2) In the interval between the lower border of the piri- 

 formis and the upper border of the superior gemellus two 

 arteries and six nerves emerge through the greater sciatic 

 foramen into the buttock, viz. : 



A . fi. Arteria glutaea inferior. 



ies ' \2. Arteria pudenda interna. 



1. Nervus glutseus inferior. 



2. Nervus cutaneus femoris posterior. 



3. Nervus ischiadicus. 



4. Nervus pudendus. 



Nerve to the obturator internus. 

 Nerve to the quadratus femoris. 



(3) In the interval between the gemellus inferior and the 

 quadratus femoris, the ascending terminal branch of the medial 



femoral circumflex artery will be seen. 



(4) At the distal border of the quadratus femoris the trans- 

 verse terminal branch of the medial femoral circumflex artery passes 

 backwards to the hamstring muscles ; and the first perforating 



i 19 c 



Nerves, 



