GLUTEAL ARTERY. 347 



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 iliacus muscle, and a small ramuscule 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 infe- 

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

 coccyx ; it first pierces and then rests upon the origin of the pyriformis, 

 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 muscle, 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 inte- 

 gument of the gluteal region. 



The Deep superior branch passes along the superior curved line of 

 the ilium, between the gluteus medius and minimus to the anterior 

 superior spinous process, where it inosculates with the superficial cir- 

 cumflexa 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 tlie Branches of the internal iliac. The most important 

 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 of 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. The obturator artery 

 may be very small or altogether wanting, its place being supplied by a 

 branch from the external iliac or epigastric. 



