) BRANCHES OF THE INTERNAL ILIAC ARTERY. 805 
‘Tlio-lumbar 
Posterior division { parietal / Lateral sacral 
j | Gluteal 
| Connie 
Seiatie 
| Internal pudic 
Anterior division - ‘Superior vesical 
(Obliterated hypogastric) 
- visceral - Middle vesical 
Inferior vesical 
Middle hemorrhoidal 
( parietal - 
In the female the inferior vesical is replaced by a vaginal branch, and an 
additional uterine branch is given off. 
BRANCHES OF THE POSTERIOR DIVISION. 
The posterior terminal division gives off the ilio-lumbar and lateral sacral 
arteries, and is continued as the gluteal artery. No visceral branches are derived 
from this division. 
1. Ilio-lumbar Artery (a. ilio-lumbalis).—This vessel runs upwards and outwards 
across the brim of the pelvis to the iliac fossa. It passes in front of the sacro-iliac 
articulation, between the lumbo-sacral cord and the obturator nerve, and behind 
either the lower part of the common or the upper part of the external iliac vessels 
and the psoas and iliacus muscles. 
In the iliae fossa it anastomoses with branches of the deep circumflex ihac and 
obturator arteries. It also gives offsets to the ihacus, and supphes a large nutrient 
branch to the ilium, A lumbar branch (ramus lum lis) ascends beneath the 
psoas to the crest of the ilium. It supphes the psoas and quadratus lumborum, 
and anastomoses with the lumbar and deep circumflex iliac arteries; it also gives 
off a spinal branch which enters the intervertebral foramen between the fifth 
lumbar vertebra and the sacrum, and is distributed like the spinal branches of the 
lumbar and aortic intercostal arteries. 
2. Lateral Sacral Arteries (aa. sacrales laterales).— There is sometimes 
only a single lateral sacral artery on each side; more commonly there are two, 
superior and inferior. 
3oth branches run downwards and inwards on the front of the sacrum. The 
inferior passes in front of the pyriformis and the sacral nerves, and descends on 
the outer side of the sympathetic cord to the coccyx where it terminates by 
anastomosing with the middle sacral. The superior branch only reaches as far as 
the first or the second anterior sacral foramen, and then it enters the sacral canal. 
It anastomoses with the lower branch and with the middle sacral artery. Transverse 
branches are given off by the lateral sacral arteries to the py riformis, and to the 
sacral nerves. Spinal offsets are also given off, which pass through the anterior 
sacral foramina to the sacral canal ; they supply the membranes of the cord, the roots 
of the sacral nerves, and the filum terminale, and anastomose with other spinal 
arteries. They then pass backwards through the posterior sacral foramina, and 
anastomose on the back of the sacrum with branches of the gluteal and sciatic 
arteries. 
3. Gluteal Artery (a. glutva superior, Figs. 569 and 575).—After giving off the 
iliolumbar and lateral sacral branches, the posterior division of the internal iliac is 
continued as the gluteal artery. This is a large vessel which pierces the pelvic 
fascia, passes backwards between the lumbo-sacral cord and the first. sacral nerve, 
and leaves the pelvis through the upper part of the great sciatic foramen. It runs 
above the pyriformis muscle to the buttock, immediately on reaching which it 
terminates, between the adjacent borders of the pyriformis and gluteus medius 
muscles and beneath the gluteus maximus, by dividing into superficial and deep 
branches. 
(a) The superficial branch divides at once into numerous branches, some of which supply 
a 
