PELVIS MINOR 457 



branches. The htmbar branch runs upwards, and terminates 

 in the substance of the quadratus lumborum and psoas major 

 muscles, where it anastomoses with the lower lumbar arteries. 

 It gives off a small spinal branch, which enters the vertebral 

 canal through the intervertebral foramen between the fifth 

 lumbar vertebra and the sacrum. The iliac branch breaks 

 up into branches, some of which run laterally in the substance 

 of the iliacus and others between that muscle and the bone. 

 One of the latter set enters the nutrient foramen in the iliac 

 fossa. The terminal branches reach the crest of the ilium, 

 where they anastomose with the deep circumflex iliac and 

 lumbar arteries. 



Arteria Glutaea Superior (O.T. Gluteal Artery). The 

 superior gluteal artery is the largest branch of the hypogastric 

 artery, and may be regarded as the continuation of its posterior 

 division. Its course in the pelvis is short. It passes back- 

 wards, between the lumbo-sacral trunk and the first sacral 

 nerve, and leaves the pelvis minor through the upper part of 

 the greater sciatic foramen, above the piriformis muscle. 



Arteria Sacralis Lateralis. The lateral sacral artery is 

 occasionally a single vessel, but more commonly it is re- 

 presented by two branches, which run medialwards, in front 

 of the sacral nerves, to the lateral borders of the anterior 

 sacral foramina. The upper of the two enters the first 

 sacral foramen. The lower runs downwards, lateral to the 

 foramina and the sympathetic trunk, and in front of the 

 roots of the sacral nerves, to the tip of the coccyx where it 

 anastomoses with the middle sacral artery. As it descends 

 it sends spinal branches into the anterior sacral foramina. 

 The spinal branches assist the upper artery to supply the mem- 

 branes and nerve-roots within the canal ; then they emerge 

 through the posterior sacral foramina and anastomose with 

 branches of the superior gluteai artery. 



Arteria Haemorrhoidalis Superior. The superior haemor- 

 rhoidal artery is the direct continuation of the inferior 

 mesenteric artery. It enters the root of the pelvic meso- 

 colon and descends in it as far as the third piece of 

 the sacrum. There it divides into two branches which 

 proceed downwards, one on each side of the rectum. 

 Each of the branches soon breaks up into smaller branches, 

 which range themselves round the gut and pierce its 

 muscular coat about the middle of its length. Within the 



