The Urethral Rhabdosphincter, Levator Ani Muscle, and Perineal Membrane: A Review
Figure 3
Horizontal sections in an 87-year-old man. Panel (a) (elastica-Masson staining) includes the urethra (UR), prostate (PR), rhabdosphincter (RS), and levator ani (LA): the anterior side of the body corresponds to the left-hand side of the figure. Panel (b) (immunohistochemistry for smooth muscle actin), panel (c) (immunohistochemistry for S100 protein), and panel (d) (immunohistochemistry for desmin) are higher-magnification views of the square in panel (a) and display thick fascia (stars) connecting the levator and rhabdosphincter areas. The connecting fascia contains abundant smooth muscle (panel (b)) and several nerves (arrows in panel (c)). Mature smooth muscle is positive for desmin (panel (d)). Panel (e), a higher-magnification view of the small area marked “E” in panel (a), exhibits irregularly arrayed elastic fibers in the connecting fascia. Scale bars: 10 mm in panel (a); 1 mm in panels (b), (c), and (d); 0.1 mm in panel (e).
