CENTRAL CONTROL OF THE BLADDER 



abortive micturition contractions is the question. 

 However, it is fair to point out that all possibility of 

 descending influences on bladder tonus are not 

 ruled out by the animal experiments since the highest 

 transections deprived the animals of much of their 

 perceptual and emotional apparatus. The intact 

 unanesthetized animals were kept in a tranquil 

 state, a requisite for obtaining a cystometrogram. 



Vesicle tonus is not a spinal or ganglionic reflex. 

 This fact has been demonstrated by Carpenter & 

 Root (5) and by Tang & Ruch (32) in experiments 

 in which any tonic mechanism depending on spinal 

 reflex arcs or postganglionic 'reflex' arcs, served by 

 the intramural plexus of the bladder wall, was 

 negated by acute spinal transection, sacral rhizotomy, 

 ganglionic blockade, ether and pentobarbital anes- 

 thesia, or anoxia (death). No change in the tonus 

 limb to the point of micturition was caused by acute 

 spinal transection (fig. 4), procainization or section of 

 the sacral roots (fig. 5), or by deep anesthesia or 

 death (fig. 6). Carpenter & Root (5) also found no 

 difference in the tonus limbs of cystometrograms for 

 normal lightly-anesthetized cats and those treated 

 with tetraethylammonium bromide (TEA) which 

 negates both the sympathetic and the parasympa- 

 thetic innervation and, presumably, mural ganglionic 

 transmission. Nesbit & Lapides (26) and Langley & 

 \Vhiteside (18) reported experiments of the same 



10 20 30 40 50 60 70 80 

 INTRAVESICAL VOLUME IN C.C. 



100 



FIG. 4. Cystometrograms comparing Segment II of the 

 normal (.V) and acute spinal preparation iSP). For significance 

 of the SUP.D and TEAC curve, see the text. [From Tang & 

 Kuch (32).] 



o 

 o 



50 . 



40 



§ 30 



g 10 



> 



-*-JU-* 



H 2C 40 60 60 100 120 140 160 

 S VOLUME -CUBIC CENTIMETERS 



FIG. 5. Cystometrogram of a cat anesthetized lightly with 

 pentobarbital ( — ) and after procainization (X) or section (•) 

 of sacral roots. [From Carpenter & Root (5).] 



weight, performed on dogs. The hypertonia after 

 pelvic nerve section, described by Langley & White- 

 side, is ascribable to exposure of the bladder. 



Cystomrtrograrn and Physical Stale of Bladder Wall 



In many experiments (figs. 14 to 16), identical 

 tonus limbs were obtained in repeated determina- 

 tions. In another set of experiments (figs. 4, 7 and 

 8), when the micturition reflex was in abeyance 

 through spinal transection, repeated cystometro- 

 grams caused the cystometric curve, especially its 

 third segment, to shift to the right after each deter- 

 mination. The only significant difference^ in the two 

 sets of experiments was the presence or absence of 

 the micturition reflex. In its absence, an initial single 

 filling of the bladder, at moderate pressures, altered 

 the tonus limb of the cystometrogram. It follows, 

 then, that the cystometrogram, rather tlian reflect- 

 ing the neurogenic tonus, reflects the physical condi- 

 tion of the bladder wall. 



If tonus and accommodation or adaptation are not 

 neurogenic, their intimate nature falls outside the 

 scope of this chapter but may be briefly indicated 

 by the following summary of Remington & 

 .Mexander's (28) recent study. The bladder wall 

 exhibits a mixture of viscous and elastic properties 



'■ In some cases, as in ligs. 4 and 7. 1, a neurectomy or a drug 

 was interposed and, at first, the shift in the tonus limb was 

 ascribed to these variables. However, the same shift occurs 

 when the cystometrogram is simply repeated, as in fig. 8. The 

 same phenomenon can be seen in the records of others before 

 and after introduction of a variable but seems to have escaped 

 notice. 



