430 



INTERNAL ILIAC ARTERY. 



PECULIARITIES. The ilio-lumbar artery sometimes arises from the internal iliac, 

 above the division of that trunk ; and more rarely from the common iliac. The iliac 

 and lumbar portions sometimes arise separately from the parent trunk. 



Fig. 294. ARTERIES OF THE BACK 

 OF THE PELVIS AND UPPER PART 

 OF THE THIGH (from Tieclemann).| 



, crest of the ilium ; b, tuber- 

 osity of the ischium and lower 

 attachment of the great sacro- 

 sciatic ligament ; c, great tro- 

 chauter ; d, integument round the 

 anus ; e, great sciatic nerve ; 1, 

 trunk of the gluteal artery as it 

 issues from tbe great sacro-sciatic 

 foramen, the superficial branches 

 cut short, the deep arch seen pass- 

 ing round on the upper part of 

 the gluteus minimus muscle ; 2, 

 placed on the great sacm-sciatic 

 ligament, points to the pudic artery 

 at the place where it winds over 

 the back of the spine of ths ischium; 

 2', the continuation of the artery 

 towards the perinseum on the in- 

 side of the tuberosity and ram us 

 of the ischium ; 3, 3, the sciatic 

 artery, the upper figure placed on 

 the pyriformis muscle, the lower 

 on the great sciatic nerve ; 4, 4', 

 first perforating artery passing 

 through the upper part of the great 

 adductor muscle and anastomosing 

 with the posterior branch of the 

 internal circumflex artery, which 

 appears between the quadratus and 

 the adductor muscles ; 5 and 6, 

 part of the second and third per- 

 forating arteries. 



When the lowest of the lumbar 



arteries is wanting it is replaced by a branch from the ilio-lumbar, which is increased 

 in size, and by a small offset from the middle sacral artery. 



VIII. LATERAL SACRAL ARTERIES. 



The lateral sacral arteries are usually two in number on eacli side, though 

 occasionally they are united into one. Tbe two arteries arise close together 

 from the posterior division of the internal iliac. One is distributed upon 

 the upper, and the other upon the lower part of the sacrum. 



Both arteries pass downwards, at the same time inclining somewhat 

 inwards, in front of the pyriform muscle and the sacral nerves, which they 

 supply with twig, and reach the inner side of the anterior sacral foramina. 

 Continuing to descend, the lower one appsoaches the middle line, and 

 anastomoses with the middle sacral artery. 



Dorsal Branches. The lateral sacral arteries give off a series of branches 

 \vhich enter the anterior sacral foramina. Each of these, after having 

 furnished within the foramen a spinal branch, which ramifies on the bones 

 ami membranes in the interior of the sacral canal, escapes by the cor- 

 responding posterior sacral foramen, and is distributed upon the dorsal 

 surface of the eacrnm. 



