THE RENAL DUCTS 1015 



tlu' untrustworthy indications afforded liy adnieusjurement after the removal of the 

 structure from the l)ody. 



Course and relations. — The tuhes lie about three inches apart at their com- 

 mencement, but this distance gradually lessens to about two inches as they descend 

 towards the sacro-iliac joint. In the true pelvis they at first diverge, but finally on 

 nearing the base of the bladder run forwards and inwards to pierce the wall of the 

 viscus, and at their termination are separated b}' a distance of about an inch 

 ( 25 nnn. ). The course of each tube may be conveniently divided into three stages, 

 abdominal, pelvic, and vesical. The abdominal portion, running downwards and 

 slightly inwards, is in relation, poster iorlij, with the psoas and its fascia, and tlie 

 genito-crural nerve, and with the common iliac artery near its bifurcation. Ante- 

 riorly, it is covered by peritoneum and intestines, and is crossed by the colic and 

 spermatic vessels. Internally, it is opposed on the right side to the inferior vena 

 cava, on the left to the aorta; the vein being almost in contact Avitli the right ureter, 

 while the artery is separated from the left tube by an interval that gradually dimin- 

 ishes from one inch above to half an inch opposite the bifurcation of the vessel. 

 In the fciDale tlic utero-ovarian veins lie on its inner side. 



The pelvic portion runs in front of the saero-iliac synchondrosis, then ui)on the 

 obturator intcrnus and its fascia Ix'hind and below the psoas, and on the outer side 



Fig. G16. — Upper Portiox of Duct. (After Heule.) 



INFUNDIBULUI/ 



SUPERIOR PELVIS 



C3MM0N PELVIS 



INFERIOR PELVIS 



of the pelvic coils of intestine (sigmoid colon on left side, small intestine on right), 

 tinally leaving the pelvic wall to join the bladder. In this ])Osition, in the male it 

 is crossed superi(jrly and internally by the vas deferens, and lies under cover of the 

 free, extremity of the vesicula seminalis, separated from its fellow by a distance of 

 an inch and a half (37 mm.). In the female it runs parallel with, and four to six 

 lines (8 to 12 mm.) from, the cervix uteri, V>ehind the uterine artery, tlirough the 

 uterine j^lexus oi vt'ins, and Ijcneath tlierootof the l)r<)ad ligament; tinally crossing 

 the upper third of the vagina to reach the vesico-vaginal interspace and jnerce the 

 bladder oi)})osite the middle of the vagina. A calculus in the lower end of the tul)e 

 might be detected l)y a vaginal examination. 



The vesical portion, al)OUt lialf an inch (12 mm.) in length, runs obliquely 

 downwards and inwards througli tlie coats of the l>ladder, and opens on to the 

 mucous surface at a distance of about three-quarters of an inch to an inch (18 to 

 25 nmi.) from its fellow, and from tlie internal urinary meatus. 



Structure. — The wall of the ureter is al)out a twenty-fifth of an inch (1 nnn.) 

 in thickness, and consists of a nnicous mem])rane. a muscular coat, and an external 

 connective tissue investment. The mucous membrane is longitudinally plicatecl, 

 and is lined with a multiple layer of transitional i]iithelium, continuous with that 



