The Urethral Rhabdosphincter, Levator Ani Muscle, and Perineal Membrane: A Review
Figure 9
Sagittal sections in a 91-year-old man and an 88-year-old woman. Panel (a) (azan staining) and panel (c) (elastica-Masson staining) display the urethra (UR) and rhabdosphincter area (RS) in a 91-year-old man and an 88-year-old woman, respectively. In panel (a), the rectourethralis muscle (RUM; smooth muscle) is seen between Cowper’s gland (CG) and the rectum (REC). Panel (c) includes the urethral opening to the bladder (BL). Panels (b) and (d) (nerve mapping) display nerve distributions according to S100 protein immunohistochemistry using sections adjacent to those in panels (a) and (c). In both genders, abundant nerves are evident on the posterior side of the urethra (UR). Panel (e) (nNOS immunohistochemistry), panel (f) (vasoactive intestinal polypeptide: VIP), and panel (g) (tyrosine hydroxylase: TH) are higher-magnification views of a nerve near the vaginal wall (VAG). The abundant VIP-positive fibers characterize female pelvic nerves. Panels (a)–(d) ((e)–(g)) were prepared at the same magnification. Scale bars: 10 mm in panel (a) and 0.1 mm in panel (e). BP: bulbus penis; BS: bulbospongiosus muscle; DTP: deep transverse perineal muscle; PR: prostate.
