Vesical Branches Research Articles

Postural change and straining induced by distension of the rectum, vagina and urinary bladder of decerebrate dogs

In decerebrate dogs, stimulation of pelvic afferent fibres and distension of the rectum, vagina and urinary bladder brought about a sustained postural change and rhythmic abdominal compression. The posture, which resulted from flexion of the back and stifle joints, extension of the hip joints and lifting of the tail, was rhythmically intensified with the abdominal compression. The sustained and rhythmic postural changes are similar to those observed in conscious dogs during defaecation. Intratracheal pressure increased with the abdominal compression. Nervous outflow to the muscles of the glottis, diaphragm, abdominal wall, tail and rear legs changed as would be expected from both the postural changes and the increases in intratracheal and intra-abdominal pressure. Nervous outflow to the external sphincter muscles of the anus and urethra increased simultaneously with both kinds of postural change; however, the increased outflow to the anus was suppressed when defaecation was initiated, and the outflow to the urethra was suppressed when micturition was initiated. In about one-third of the dogs, decreases in the outflow of the pelvic rectal branch and slight increases in the outflow of the vesical branch occurred synchronously with the abdominal compression. These results show that postural change and straining for defaecation, micturition and parturition are reflexly organized by the lower brainstem and the spinal cord.

An electrophysiological study of somatic and visceral convergence in the reflex control of the external sphincters.

1. Mass wave and single unit discharges have been recorded from pudendal efferents innervating the external anal and urethral sphincters in chloralose anaesthetized or decerebrate cats.2. Reflex discharges in these neurones were elicited by electrical stimulation of the contralateral pudendal nerve, the posterior cutaneous nerve of thigh, or the vesical or colonic branches of the pelvic nerve. The latencies of the evoked responses were 5.5-20 msec. The vesical branches of the pelvic nerve produced discharges less consistently than the other nerves.3. Irrespective of whether afferent stimulation produced an early evoked response there was always a prolonged period of depression of pudendal nerve excitability following the stimulus. Condition-test interactions showed that this depression began within 50 msec of the stimulus and that its duration varied between 150 and 2500 msec in single units, with a modal value of 500 msec.4. No evoked response or depression of excitability was seen when afferents in the hypogastric or lumbar colonic nerves were stimulated.5. Increasing intravesical or intracolonic pressure, within physiological limits, produced a graded reduction in the size of evoked discharges.6. Short trains of stimuli (four shocks in 20 msec) applied to the raphé nucleus, were capable of inhibiting test responses in pudendal efferents for periods of up to 800 msec.7. The possible functional roles of two groups of sphincteric reflex interneurones, with either excitatory or inhibitory receptive fields, are discussed.

Factors that determine the excitability of parasympathetic reflexes to the cat bladder.

1. Spino-bulbo-spinal reflex responses could be recorded from the vesical branches of the pelvic nerve following electrical stimulation of afferents in the vesical or colonic branches of the pelvic nerves, the hypogastric or pudendal nerves. The latencies of responses from these different sources were similar.2. Short latency responses could be recorded from the vesical branches of the pelvic nerve on electrical stimulation of descending pathways in the spinal cord and ipsilateral to and just below a hemitransection at the second cervical segment.3. These responses were facilitated by increases in intravesical pressure, maximal facilitation occurring at about 30 mmHg. Conversely, increases in intracolonic pressure inhibited these parasympathetic evoked responses, the maximum effect being seen with intracolonic pressures of 40-50 mmHg.4. These results suggest that the spino-bulbo-spinal responses that are recorded from the vesical parasympathetic efferents can be elicited from nerves innervating viscera other than the bladder, and also somatic structures. The effects of these spino-bulbo-spinal pathways on vesical parasympathetic efferents are dependent on antagonistic influences of intravesical and intracolonic pressure.5. The pathways that mediate the changes in excitability in these reflexes appear to act at least in part at the termination of the bulbo-spinal limb of the reflex, and involve afferents in the pelvic nerves but not the hypogastric or lumbar colonic nerves.6. It is proposed that the neurones that mediate this ;gating' action on the excitability of pelvic nerve reflexes are located in the sacral cord, and form a proportion of the population of interneurones described by McMahon & Morrison (1982b). In addition it is proposed that the neurones which mediate the ascending limb of the spino-bulbo-spinal reflexes are the long ascending neurones described by McMahon & Morrison (1982a).

Inhibitory interactions between colonic and vesical afferents in the micturition reflex of the cat.

1. In anaesthetized cats in which the only intact autonomic pathways innervating the colon and bladder were in the pelvis nerves, distension of the colon resulted in a graded inhibition of spontaneous bladder motility, and a decrease in the reflexly evoked waves of activity in the vesical branches of the pelvic nerves. 2. Electrical stimulation with voltages sufficient to excite only the myelinated fibres in the colonic branches of the pelvic nerve caused inhibition of spontaneous bladder motility, an increase in micturition threshold, and a reduction in the reflexly evoked waves of activity in the vesical efferents of the pelvic nerve. 3. The results demonstrate that the pelvic nerve afferent inflow from the colon produces a marked central inhibitory influence on the micturition reflex.

The arterial supply of the urinary bladder.

(1) The urachal artery has a primary origin from the umbilical artery itself, and is at first bilateral. (2) The arterial pattern in newborn infants is not identical to that of adults. Obliteration of the umbilical artery in older infants carries with it obliteration of some of its branches, especially at their origin from its distal part, with a resulting change in arterial pattern. (3) The middle vesicle artery is a fairly constant branch of the umbilical artery, supplying the bladder neck and the front of the bladder above the neck. (4) The urachal and middle vesicle arteries, when unilateral, occur with equal frequency on both sides. (5) The anastomosis between superior vesical and inferior episgastric arteries was confirmed in the subperitoneal tissues, but was very rare in the wall of the bladder, occurring only when an abnormal obturator artery was the source of a superior vesical branch. (6) The constancy of the vesiculo-deferential artery is confirmed.

Changes in vesical function produced by cutaneous stimulation in rats

(1) The effect of stimulation of various skin areas on the function of the bladder was examined in anesthetized rats with the CNS intact, in decerebrated non-anesthetized rats and in spinal rats. The tone and contraction of the bladder was measured by the intravesical balloon method. (2) When the volume of the intravesical balloon was expanded so that the resting vesical pressure was increased from 0 to approximately 40 mm H 2O level, the bladder revealed small spontaneous contractions in all experiments. Under these conditions intravesical pressure was increased approximately 40 mm H 2O by application of tactile or nociceptive stimulation of the skin in the perineal area. This excitatory perineal-bladder response existed before and after spinal transection and was shown to be a propriospinal reflex for which reflexly increased nerve discharges of vesical branches of the pelvic nerves were responsible. (3) When the volume of the intravesical balloon was further expanded so that the resting vesical pressure was kept about 200 mm H 2O, the bladder had the usual large rhythmic contractions (micturition contractions) with amplitudes of about 610 mm H 2O, and rhythms of 1–3/min in the CNS intact or decerebrated rats. These large contractions were driven by the rhythmic bust discharges of the vesical nerve branches of the pelvic nerves. The occurrence of the large contractions of the bladder could be inhibited by nociceptive stimulation which was localized in the perineal area. This inhibition of the large contractions was caused by disappearance of the rhythmic burst discharges in the vesical branches of the pelvic nerves. (4) On some occasions in the CNS intact anesthetized and in the decerebrated non-anesthetized rats the large contractions of the bladder disappeared during experiments even when the bladder was expanded enough for producing normal large contractions and kept at high intravesical pressure. Regardless of whether the large contractions existed or not at the high intravesical pressure, the vesical pressure was increased by perineal stimulation due to the same neural mechanism mentioned in (2) above.

Carcinoma of the seminal vesicle--with particular reference to the angiographic appearances.

Summary The angiographic findings in a case of primary adeno-carcinoma of the seminal vesicle have been presented. The arteriographic features were those of vascular neoplasms in general; involvement of the middle vesical branches of the hypogastric artery may, however, suggest the diagnosis.

THE PELVIC AND PERINEAL FASCIAE AND THEIR NEURAL AND VASCULAR RELATIONSHIPS.

AbstractThis study was based upon a dissection of the pelvic fasciae and associated structures of one hundred and three adult pelves as well as those of three full term fetuses. The perineal fasciae and their neural and vascular relationships were studied in an additional 55 specimens.The uterovaginal fascia, as stated by others, is a well‐defined structure. One is usually able, on the basis of a fascial cleft, to distinguish readily between the fascial sheath of rectum proper and the deeper layer of subperitoneal fascia, called by some the presacral fascia. The latter is described, including the relationship of the pelvic autonomics thereto. The relationship of the vesical branches of the pelvic plexus and of the venous plexuses to the terminal ureter are also described.We were able to confirm the presence of a superficial and a deep perineal fascia; the latter forms the inferior boundary of the superficial perineal space proper, as described by others. The relationship of particular nerves (and vessels) to the fascial planes of the perineum follows a definite pattern even when variation from the normal is present.