562 THE ARTERIES 



THE OVARIAN ARTERIES 



The ovarian arteries are the honiologues of the spermatic arteries in the male, 

 and correspond in their relations in the ui)per part of their course. Tliey diverge 

 somewhat less however, and on reaching the level of the connnon iliac artery turn 

 inwards over that vessel and descend tortuously into the pelvis hetween the folds 

 of the Inroad ligament to the ovaries. In the broad ligament the ovarian artery lies 

 below the Fallopian tube, and on reaching the ovary turns backwards and sujjplies 

 that organ (fig. 370). 



They give off the following branches: — (1) Ureteral; (2) Fallopian; (3) uterine; 

 and (4) ligamentous. 



(1) The ureteral is distributed, as in tlie male, to the ureter. 



(2) The Fallopian supplies the istlnnus and ampulla of the Falloi)ian tu])e and 

 its fimbriated extremity. 



(3) The uterine runs along the Fallopian tulje to the superior cornu of the 

 uterus, which it supplies, together -with the upper jtart of the fundus uteri, and 

 anastomoses with the uterine arteries from the internal iliac. 



(4) The ligamentous is distributed to the round ligament, passing with that 

 structure through the inguinal canal, and anastomosing with the cremasteric and 

 superficial external pudic arteries. 



Like the spermatic, the ovarian arteries in the foetus come off at right angles to 

 the aorta, and pass transversely outwards to the ovaries, which are formed, as are 

 the testicles, in the right and left loin in front of the kidneys. They elongate as 

 the ovaries descend into the pelvis. During pregnancy these arteries undergo great 

 enlargement. 



THE INFERIOR MESENTERIC ARTERY 



The inferior mesenteric artery, smaller than the superior, arises from the 

 front of the al)dominal a(jrta about an inch and a half above the bifurcation of that 

 vessel. It runs oblicpiely downwards and to the left, across the lower part of the 

 abdominal aorta and then over the left psoas muscle and left common iliac artery, 

 descends into the pelvis l:)etween the layers of the meso-rcctum, and terminates on 

 the rectum in the superior hemorrhoidal or superior rectal artery. It at first lies 

 behind the peritoneum, or in the left lumbar meso-colon Avhen that structure is 

 })resent. It supplies the lower half of the large intestine. Its vein lies at first close 

 to the left side, but soon passes upwards on the psoas, away from the artery, to 

 end in the splenic vein (fig. 367). 



The branches of the inferior mesenteric are: — (1) The left colic; (2) the 

 sigmoid; and (3) the superior hemorrhoidal. 



(1) The left colic runs transversely outwards and to the left, 1)eneath the peri- 

 toneum, and divides into two Ijranches, one of which, entering the transverse meso- 

 colon, ascends upwards and to the right, to anastomose with the middle colic. The 

 other descends, and, entering the sigmoid meso-colon, anastomoses with the 

 ascending branch of the sigmoid artery. 



The distribution of this artery and the next to the colon is similar to that of 

 the colic branches of the superior mesenteric, and does not require a separate 

 description. (See Superior Mesenteric Artery, pages 559, 560.) 



(2) The sigmoid artery runs downwards and to the left over the psoas muscle, 

 and, entering the sigmoid meso-colon, divides into two liranches; the ui)per anasto- 

 mosing with the left colic, the lower with the superior luemorrhoidal. 



(3) The superior haemorrhoidal is the continued trunk of the inferior mesen- 

 teric. It descends into the pelvis, behind the rectum, between the layers of the 

 meso-rectum. On reacliing the wall of the bowel it l)ifurcates, one branch proceed- 

 ing on either side of the gut, to within four or five inches of the anus. Here each 

 again divides, and the branches, piercing the muscular coat, descend between that 

 coat and the mucous membrane, forming with each other, and with the middle 

 hcDmorrhoidal arteries — derived from the internal iliac — a series of small vessels, 

 running longitudinally to the rectum, and ])arallel to each other as far as the level 



