he tubes are supplied richly with elastic tissue, blood vessels, and lymphatics. Their sympathetic innervation is extensive, in contrast to their parasympathetic innervation. This nerve supply derives partly from the ovarian plexus and partly from the uterovaginal plexus. Sensory aferent ibers ascend to T]o spinal cord levels.
Anteriorly, the bladder rests against the inner surface of the pubic bones and then, as it fills, also against the anterior abdominal wall. Posteriorly, it rests against the vagina and cer vix. he bladder is divided into a dome and a base approximately at the level of the ureteral oriices. The dome is thin walled and distensible, whereas the base is thicker and undergoes less distention during filling. The vesical trigone lies in the bladder base and contains both ureteral oriices and the internal
A B FIGURE 2-14 The fallopian tube of an adult woman with cross-sectioned illustrations of the gross structure in several portions: (A) isthmus, (B) ampUlla, and (C) infundibulum. Below these are photographs of corresponding histological sections. (Used with permission from Dr. Kelley S. Carrick.) urinary meatus (see Fig. 2-11). he urethral lumen begins at this meatus and then courses through the bladder base for less than 1 cm. This region where the urethral lumen traverses the bladder base is called the bladder neck.
The bladder wall consists of coarse bundles of smooth muscle known as the detrusor muscle, which extends into the proximal part of the urethra. A submucosal layer intervenes between this detrusor muscle and the mucosa. he bladder mucosa consists of transitional epithelium and underlying lamina propria.
The blood supply to the bladder arises from the superior vesical arteries, which are branches of the patent portion of the umbilical artery, and from the middle and inferior vesical arteries, which, when present, often arise from either the internal pudendal or the vaginal arteries (see Fig. 2-12). The nerve supply to the bladder arises from the vesical plexus, a component of the inferior hypogastric plexus (see Fig. 2-13).
As the ureter enters the pelvis, it crosses over the bifurcation of the common iliac artery and passes just medial to the ovarian vessels (see Fig. 2-10). As the ureter descends into the pelvis, it lies medial to the internal iliac branches and anterolateral to the uterosacral ligaments. The ureter then traverses through the cardinal ligament approximately 1 to 2 cm lateral to the cervix. Near the level of the uterine isthmus, it courses below the uterine artery and travels anteromedially toward the bladder base. In this path, it runs close to the upper third of the anterior vaginal wall (Rahn, 2007). Finally, the ureter enters the bladder and travels obliquely for approximately 1.5 cm before opening at the ureteral oriices.
The pelvic ureter receives blood supply from the vessels it passes: the common iliac, internal iliac, uterine, and superior vesical vessels. The ureter's course runs medial to these vessels, and thus its blood supply reaches the ureter from lateral sources. This is important during ure teral isolation. Vascular anastomoses on the connective tissue sheath enveloping the ureter form a longitudinal nenvork of vessels.
The pelvis is composed of four bonesthe sacrum, coccyx, and two innominate bones. Each innominate bone is formed by the fusion of three bones-the ilium, ischium, and pubis (Fig. 2-15). Both innominate bones are joined to the sacrum at the sacroiliac synchondroses and to one another at the symphysis pubis.