TIH-: I-:\Ti:i;\.\L ILIAC AHTMir- 545 



branch in Solipeda; it escapes frem tin- jiclvic cnvity with the great sciatic 

 nerve, which it :iecoin| anies to behind the thigh, win re it is C\JM nded, after giving oflf 

 <ui its course spinal and glnteal twigs. It is not this brunch which supplies tho coccy- 

 j' nl niti ri't : these mine, jis in (hi- l'ig and Kiiiiiiiiant*, from tho middle sacral artery. 



COMPARISON Of TUE INTERNAL ILIAC ARTERIES IN MAN WITH THOSE OF ANIMALS. 



The aorta in Man bifurcates at tho fourth lumbar vertebra to form the primitive (or 

 iHiimini) iliac arteries, which descend to each side of the margin of the pelvis, where 

 they divide into two branches, the internal and external iliacs. 



The !nt, riKil iliin; or Jiyftonafiric artery, passes beneath the sacro-ilinc articulation, 

 imd breaks uji into nine or eleven branches that go to the walls of the pelvic cavity, or 

 to the organs conlaine.I in it. Their li.spo.-itioii .-omewhat resembles that of Car- 

 nivor.i: in their di.-trihiition they n -present the various branches of the internal iliac of 

 Soii|H'ds. Tlius we lind : I, An iimliih'i-nl rt> nj ; 2, Tho vesifo-prostatic artery, re- 

 r-emhling tlie branch of the same name given oft' in the Horse by the internal pudic ; 

 3, The midiUi- li:< ,i,arrliitlal nrt< ry, that parses to the rectum like the branch of tho 

 internal pudic; 4, The ilra-lnmlar artirij,i\\e iliacn-muscular of Solipeds; 5, The lateral 

 facnil artery. which, behind, joins the middle sacral instead of dividing, as in the Horse, 

 into ischiatic and lateral coecygeal ; 6, Tlic obturator artery ; 7, Gluteal artery ; 8, Is- 

 rlu'iitic; !, lul, rital jimlir, that terminate!", as in animals, by the cavernous, dorsalis 

 jx'iiis. and the transversa ]>erinei arteries. The arterial branches of tho rectum, or 

 inferior haemorrhoidal, arc furnished by the internal pudic artery. 



ARTICLE IV. EXTERNAL ILIAC AIITERIBS on CRURAL TRUNKS. (Fig. 277, 11.) 



Tho external branches of the terminal quadrifurcations of the posterior 

 aorta, the crural trunks descend on the sides of the entrance to the pelvic 

 cavity, in describing a curve downwards and forwards, and a direction 

 oblique from above to below, before to behind, and within outwards. 

 Maintained within the small psoas and iliacus muscles by the peritoneum 

 covering them, they are bordered posteriorly, and to tho inner side, by 

 the iliac vein, which isolates them from the pelvic trunk. When they 

 arrive at the anterior border of the pubis, in tho interstice which separates 

 tho pectineus from tho long adductor of tho leg, each is prolonged to 

 tho thigh, and takes tho namo of femoral artery ; and thence into the angle 

 of tho fcmoro-tibial articulation, where it receives tho denomination of 



D-foro passing to the description cf these two vessels continuations 

 of the external iliac artery, wo will indicate tho collateral branches which 

 c iiiiinato from this trunk itself. These are two principal: tho xj/i// 

 ti*li<-nlr or uterine (cremasteric), and tho cifCHnijli-.ni Hi!. The first having 

 been already described (p. 534), wo have only to notice the second. 



CIRCUMFLEX ILIAC AKTKRY (Fig. 272, 11). This artery commences at 

 an acuto angle near tho origin, and in front of, tho external iliac ; it 

 sometimes emerges directly from tho abdominal aorta. It is directed 

 outwards, passes between tho peritoneum and tho lumbo-iliac apoucurosis, 

 ami arriving at tho external border of the great psoas muscle, or even 

 iM-yiiul that, it bifurcates. The nnt> rior branch sends its ramifications into 

 the InmsvrrM- and wnall oblique muscles of tho abdomen, where they 

 anastomose with the abdominal ramuscules of tho lumbar and intercostal 

 brandns; the i^tiri<>r lii/'m-cation, after giving some vessels to tho same 

 muscles, traverses tho abdominal wall a little below tho external angle of the 

 ilium, in passing between the small oblique and iliacus muscles, to deso ml 

 within tin anterior bordor of the ilio-aponcim.ticns (tensor vagina;) muscle, 

 and expend itself in front of the thigh by Mibcnt.ine.nis divisions. 



2 N 



