Polarization optic investigations on the anatomy of the bladder neck and the vesical fundus in women.

On the basis of an investigation technique, not so far applied in the urinary bladder, whole-organ preparations were rendered transparent and examined at supramicroscopic magnifications. The results available so far with regard to the fiber structure of the neck of the bladder and the vesical fundus were checked in 12 female urinary bladders. The following results were obtained: (1) the structure of the posterior longitudinal muscle is confirmed, as already described previously; (2) an anterior longitudinal muscle almost symmetrical to the posterior longitudinal muscle is demonstrated, and (3) the fiber course of the base plate has so far been described as running in the form of a horseshoe around the urethra. We see that in their main portions the fibers cross under the margins of the deep trigonum, then change their direction and turn laterodorsally, thus acting subtrigonally in the median line. The construction of the investigation instrument and the investigation technique are described in detail. The investigation results are discussed in the context of anatomical and physiological knowledge.