VESSELS AND NERVES OF THE PELVIS. 518 



SECTION IV. 



VESSELS AND NERVES OF THE PELVIS. 



IN the pelvis are contained the internal iliac vessels, and their branches 

 to the viscera ; the sacral plexus and its nerves ; and the sympathetic 

 nerve. This Section is to be used by the dissectors of both the male and 

 female pelvis. 



Directions. The internal iliac vess'els are to be dissected on the right 

 side. But the air should be previously let out of the bladder ; and this 

 viscus and the rectum, with the uterus and the vagina in the female, should 

 be drawn aside from their situation in the centre of the pelvis. 



Dissection. The loose tissue and fat are to be removed from the trunks 

 of the vessels, as well as from the branches of the artery that leave the 

 pelvis, or supply the viscera ; and the obliterated cord of the hypogastric 

 artery is to be traced on the bladder to the umbilicus. 



With the vessels are offsets of the hypogastric plexus of nerves, but 

 these will probably not be seen ; but in dissecting the vessels to the bladder 

 and rectum, branches of the sacral spinal nerves will come into view. The 

 veins may be removed in a general dissection, to make clean the arteries. 



When the vessels are prepared the bladder may be again distended, and 

 the viscera replaced. 



The INTERNAL ILIAC ARTERY (fig. 176, g) is one of the trunks result- 

 ing from the division of the common iliac artery, and furnishes branches 

 to the viscera and wall of the pelvis, to the generative and genital organs, 

 and to the limb. 



In the adult the vessel is a short trunk of large capacity, which meas- 

 ures about an inch and a half in length. Directed downwards as far as the 

 sacro-sciatic notch, the artery terminates generally in two large pieces, 

 from which the several offsets are furnished. From the extremity a partly 

 obliterated vessel (hypogastric) extends forwards to the bladder. 



In entering the pelvis the artery lies in front of the lumbo-sacral nerve. 

 It is accompanied by the internal iliac vein, which is posterior to it, and 

 somewhat to the outer part on the right side. 



The branches of the artery are numerous, and arise usually in the fol- 

 lowing manner : From the posterior piece of the trunk three arise, viz., 

 the ilio-lumbar, lateral sacral, and gluteal. And from the anterior portion 

 come the vesical (upper and lower), haemorrhoidal, obturator, sciatic, and 

 pudic : in the female there are in addition the uterine and vaginal 

 branches. 



Artery in the foetus. In the foetus the hypogastric artery takes the 

 place of the internal iliac, and leaves the abdomen by the umbilicus. At 

 that time it is larger than the external iliac artery ; and, entering but 

 slightly into the cavity of the pelvis, it is directed forwards to the back of 

 the bladder, and along the side of that viscus to the apex. 



Beyond the bladder the artery ascends along the posterior aspect of the 

 abdominal wall with the urachus, converging to its fellow. Finally at 

 the umbilicus the vessels of opposite sides come in contact with the um- 

 bilical vein, and passing from the abdomen through the aperture at that 

 spot, enter into the placental cord, and receive the name umbilical. 



In the foetus, branches similar to those in the adult are furnished by the 

 artery, though their relative size at the two periods is very different. 

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