810 THE VASCULAR SYSTEM. 
. Sciatic Artery (a. gluta inferior, Figs. 569 and 57 
71).—The sciatic artery 
arises, usually distinct from the pudic artery, but sometimes in common with it, from 
_ Gluteus medius 
Gilacenstmanna Gluteus minimus 
uteus max S 
Deep branch of 
gluteal artery 
Great sciatic : 
ligament—— Pyriformis 
Internal 
pudic artery 
Obturator internus 
and gemelli 
Ascending branci 
of internal 
circumflex artery 
Sciatic artery 
Comes nervi 
— Quadratus femoris 
Biceps and 
semitendinosus ane velee branch 
of interna 
circumflex artery 
Semimembranosus 
Ist perforating 
— artery 
2nd perforating 
Muscular branch ~ artery 
of profunda artery — 
3rd perforating 
— artery 
Termination of 
profunda artery 
(4th perforating) 
—_ Short head of biceps 
Long head of biceps 
Popliteal artery_— 
—— Popliteal vein 
Superior external articular 
Superior internal 
artery 
articular artery 
Semitendinosus 
Gastroenemius —— 
Gastroenemius 
Muscular artery — 
Fic. 571.—THE ARTERIES OF THE BUTTOCK AND THE BACK OF THE 
THIGH AND KNEE. 
the anterior division 
of the internal ihae. 
It descends a little 
behind and external 
to the pudie vessels, 
pierces the pelvic 
fascia, runs back- 
wards between the 
first and second, or 
second and third 
sacral nerves, and 
passing between the 
pyriformis and coc- 
eygeus muscles, 
leaves the pelvis 
through the lower 
part of the great 
sciatic foramen, and 
enters the buttock 
just below the pyri- 
formis. In the but- 
tock it descends be- 
hind and to theinner 
side of the great 
sciatic nerve beneath 
the gluteus maxi- 
mus, and over the 
obturator internus, 
the two gemelli, the 
quadratus femoris, 
and upper part of 
the adductormagnus 
muscles, to the upper 
part of the thigh. 
Below the lower 
border of the gluteus 
maxunus the artery 
is comparatively 
superficial, and 
having given off its 
largest branches, it 
descends as a long 
slender vessel with 
the small sciatic 
nerve. 
Branches. — Jn 
the pelvis.—Small and 
irregular branches 
supply the adjacent 
viscera and muscles 
and the sacral nerves ; 
they anastomose with branches of the internal pudic and lateral sacral arteries. 
In the buttock. 
buttock and to the upper parts of the hamstring aeaialon. 
pudic, internal circumflex, and obturator arteries. 
immediately after the artery leaves the pelvis. 
— (a) Muscular branches are given off to the muscles of the 
They anastomose with the 
(4) The coccygeal branch arises 
It runs inwards, pierces the great 
sacro-sciatic ligament and the eluteus maximus, and ends in the soft tissues over the | 
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