GLUTEAL ARTERY. 311 



and inosculates with the internal circumflex artery. And an external 

 branch which pursues its course along the outer margin of the 

 obturator foramen to the space between the gemellus interior and 

 quadratus femoris, where it inosculates with the ischiatic artery. 

 In its course backwards it anastomoses with the internal circumflex, 

 and sends a branch through the notch in the acetabulum to the hip- 

 joint. Within the pelvis the obturator artery gives off a branch to 

 the iliac us muscle, and a small ramiiscule which inosculates with 

 the epigastric artery. 



The LATERAL SACRAL ARTERIES are generally two in number on 

 each side ; superior and inferior. The superior passes inwards to 

 the first sacral foramen and is distributed to the contents of the 

 spinal canal, from which it escapes by the posterior sacral foramen, 

 and supplies the integument on the dorsum of the sacrum. The 

 inferior passes down by the side of the anterior sacral foramina to the 

 coccyx ; it first pierces and then rests upon the origin of the pyri- 

 formis, and sends branches into the sacral canal to supply the sacral 

 nerves. Both arteries inosculate with each other and with the sacra 

 media. 



The GLUTEAL ARTERY is the continuation of the posterior trunk 

 of the internal iliac : it passes backwards between the lumbo-sacral 

 and first lumbar nerve through the upper part of the great sacro- 

 ischiatic foramen, and above the pyriformis muscles, and divides 

 into three branches superficial, deep superior, and deep inferior. 



The Superficial branch is directed forwards between the gluteus 

 maximus and medius, and divides into numerous branches, which 

 are distributed to the upper part of the gluteus maximus and to the 

 integument of the gluteal region. 



The Deep superior branch passes a^ong the superior curved line 

 of the ilium, between the gluteus medius and minimus to the ante- 

 rior superior spinous process, where it inosculates with the superfi- 

 cial circumflexa ilii and external circumflex artery. There are 

 frequently two arteries which follow this course. 



The Deep inferior branches are several large arteries which 

 cross the gluteus minimus obliquely to the trochanter major, where 

 they inosculate with branches of the external circumflex artery, and 

 send branches through the gluteus minimus to supply the capsule of 

 the hip-joint. 



Varieties in the Branches of the internal iliac. The most impor- 

 tant of the varieties occurring among these branches is the origin 

 of the dorsal artery of the penis from the internal iliac or ischiatic. 

 The artery in this case passes forwards by the side of the prostate 

 gland, and through the upper part of the deep perineal fascia. It 

 would be endangered in the operation for lithotomy. The dorsal 

 artery of the penis is sometimes derived from the obturator, and 

 sometimes from one of the external pudic arteries. The artery of 

 the bulb, in its normal course, passes almost transversely inwards to 

 the corpus spongiosum. Occasionally, however, it is so oblique in 

 its direction as to render its division in lithotomy unavoidable. 



