Abstract
A considerable number of intraproprial and intraepithelial sensory termnations were found in the peripheral parts of the trigonum vesicae and in the vicinity of the orificium urethrae internum of the human urinary bladder.
The intraproprial terminations comprise branched terminations and corpuscular ones, the former again are classifibale into those formed of fine terminal fibres and those of thick terminal fibres, while the latter comprise capsulated and uncapsulated genital nerve bodies Type I and Type II.
The branched terminations composed of fine terminal fibres are usually of simple type and are formed of thin fibres running little winding courses and showing little change in size and end widely spread out in not only the superficial but also the deeper layers of the propria.
The branched terminations composed of thick terminal fibres originate in thick sensory fibres and comprise three subtypes as follows. The terminations Type I are subepithelial branched ones, sometimes of very complex plexus-like form, composed of thick terminal fibres showing conspicuous change in size during their complex looped courses. The Type II of these terminations is represented by terminations composed of sensory fibres showing little change in size during typical wavy courses and a few thick terminal fibres sent out from them, found spread out over a wide area in the propria. The terminations of Type III are of simple branched type, but are characterized by the round or oval neurofibrillar expansions of considerable size found on some of the terminal fibres.
The corpuscular terminations formed subepithelially comprise ccapsulated and uncapsulated ones, both of which belong to the small-sized genital nerve bodies Type I or Type II. The genital bodies Type I show glomerular arrangement of the terminal fibres in their inner bulb, while those of Type II have branched terminations formed of comparatively few terminal fibres therein. Among the capsulated end bodies Type II some of compound type were often found, formed of several of such bodies aggregated at one place. In such compound bodies, a part of the connective tissue capsule pressed between the densely packed individual component bodies is forced out of exsitence.
The uncapsulated genital nerve bodies are generally smaller in size than the capsulated ones and are sometimes very small indeed. These also contain branched or glomerular terminations of sensory fibres in their dark-staining inner bulb. That is, these small end bodies also comprise genital nerve bodies Type I and Type II. Very frequently, two such uncapsulated end bodies are formed by the same stem fibre and often fine intraepithelial fibres are sent out from some genital bodies of this type.
Intraepithelial sensory terminations are found in the transitional epithelium of the urinary bladder in a considerable number. These are not formed only of fine and medium-sized branch fibres, as reported hitherto, but also of thick and thin branch fibres originated in thick stem fibres: even very complex plexiform and glomerular terminations formed of considerably thick fibres never found in any other part of the human body were not rare in this epithelium of the urinary bladder. These are rather interesting entities, when we consider their exclusive presence in the vesical epithelium and their highly probable free mobility.
