The ureter
The ureter is 10 inches (25 cm) long. It comprises a pelvis and
an abdominal, pelvic and intra-vesical portion. It is narrowed
at three sites: the pelvi-ureteric junction, as it crosses into the
pelvis, and at its termination. Obviously these are where a
calculus is most likely to become lodged. The ureter descends
on the medial edge of psoas major, which separates it from the
transverse processes of L2–L5, and is crossed by the gonadal
vessels; it is at risk when these are ligated and divided in
gynaecological surgery. On the right, the ureter passes behind
the third part of the duodenum before it emerges immediately
deep to, and adherent to, the peritoneum of the posterior
abdominal wall. On the left it passes behind the apex of the
sigmoid mesocolon. It passes into the pelvis very constantly at
the bifurcation of the common iliac artery, even when this vessel
becomes tortuous and distorted in arteriosclerosis.
The pelvic ureter runs on the pelvic lateral wall in front of
the internal iliac artery, then turns forward and medially in
front of the ischial spine to enter the bladder. In the male it lies
above the seminal vesicle near its termination and is crossed
superficially by only one structure: the vas deferens. In the
female, it passes below the broad ligament and uterine vessels,
(where it may be damaged at hysterectomy), and here passes
above the lateral fornix of the vagina 0.5 inches (12 mm) lateral
to the supravaginal portion of the cervix. Once in my life I
palpated a large ureteric stone impacted at this site on pelvic
examination!