Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “URETHRA”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1988

Neurogenic urethra: clinical relevance of isolated neuropathic dysfunction of the urethra, and the denervation supersensitivity of the urethra revisited.

Our clinical experience on isolated neuropathic dysfunction of the urethra is presented. By discussing the urodynamic findings in neurogenic urethra, wherein the denervation supersensitivity to alpha-adrenergic stimulation in the absence of vesical denervation was a common denominator, some insight into the modern concept of motor innervation of the urethra was attempted. Our data are supportive of the current dogma implicating a significant sympathetic contribution to both autonomic and somatomotor innervation of the urethra.

Adult↗
PubMed1984

[The striated sphincter of the urethra. 1: Recall of knowledge on the striated sphincter of the urethra].

The first part of this report is devoted to the anatomy, nerve supply, and physiology of the striated sphincter, three subjects which greatly aroused a great deal of controversies. The conclusions of the authors are as follows. The striated sphincter of the urethra is a muscle of the perineum, arising from the cloacal sphincter. The deep transverse, bulbo-cavernous, anal sphincter, ischio-cavernous and superficial transverse muscles have the same embryological origin and together with the sphincter of the urethra form the accessory pelvic diaphragm. The embryological origin of the levator ani muscles is different. These arise from the caudal muscles and form the principal pelvic diaphragm. The striated sphincter of the urethra is unequally distributed in the male and female fetus. According to our anatomical concept, the urethral sphincter includes two structures: the para-urethral sphincter and the peri-urethral sphincter. The para-urethral sphincter form an integral part of the urethra and is distributed principally along the membranous part of urethra but extends approximately to the bladder neck and distally under the perineum aponeurosis. In the adult as in the fetus, the para-urethral striated sphincter is unequally distributed along the urethra, according to sex. In the male, it surrounds the membranous urethra and is absent from the posterior face of the prostatic urethra. By contrast, in the female, the sphincter surrounds the proximal third of the urethra and the rings are incomplete on the distal third. The peri-urethral striated sphincter includes the other muscles of the perineum and of the principal pelvic diaphragm. These two structures differ from a microscopic stand point; the para-urethral striated sphincter contains only narrow calibre slow fibers, with the absence of the neuro-muscular spindles. By contrast, the peri-urethral sphincter consists of slow and rapid fibers and contains neuro-muscular spindles. The nerve supply of the peri-urethral striated sphincter is insured by internal pudendal nerves. The para-urethral striated sphincter is supplied in great part of the same internal pudendal nerves arising from neurones situated in the nucleus of Onuf. However, the pelvic nerves may contain a group of accessory fibers from the same origin. There is no proof available as to the role played by the sympathetic nervous system. When micturition comes to an end, the para-urethral sphincter causes a constriction of the membranous urethra in the male, and single flattening of the middle part of the urethra in the female.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1997

Membrano-bulbo-urethral junction stenosis. Posterior urethra obstruction due to extreme caliber disproportion in the male urethra.

OBJECTIVE: Based on 4 cases of infravesical obstruction due to extreme caliber disproportion between the posterior urethra and the penile urethra, a pathophysiological mechanism for this dynamic obstruction is given and endoscopic treatment is described. SUBJECTS: Four cases of membrano-bulbo-urethral junction (MBUJ) stenosis, seen between September 1995 and April 1996, are described. Two boys had previous successful valve resection but still showed extreme ballooning of the posterior urethra. The other 2 boys showed bladder instability on urodynamics and the male variant of the spinning top urethra on voiding cystourethrography (VCUG). RESULTS: All cases were successfully treated by endoscopic incision at the 12 o'clock position of the kink between the posterior and the penile urethra which is seen when the full bladder is expressed. Disproportion in the posterior urethra, seen on VCUG, together with bad urinary flow measured on uroflowmetry raise the suspicion of MBUJ stenosis. CONCLUSION: Although rarely seen, extreme caliber disproportion in the male urethra can cause obstruction. Ballooning of the posterior urethra, caused by urethral valves, bladder instability resisted by voluntary sphincter contraction or congenital posterior urethral dilatation, creates an obstructive kink in the urethra comparable to some obstructions in ureteropelvic junction stenosis. If suspicion of such a form of obstruction arises, cystoscopy during pressure on the full bladder is mandatory in order to see the obstruction, descending as a membrane from the vault of the urethra.

Adolescent↗
PubMed1996

Penile bulb and its relationship with the pelvic urethra and the penile urethra in the rat: light and scanning electron microscopical observations.

BACKGROUND: In male rats the urethral tract consists of the following parts: the pelvic urethra, the transitional urethra, the urethral diverticle, and the penile urethra. Perusal of the literature results in only some more general descriptions and a very few which go more into detail. None of the latter deals with all the compartments nor with the relationships between each other. Aim of this study is to give a detailed morphological study of all the urethral compartments and their relationships to provide a platform for further experimental investigations. METHODS: From 40 adult male Wistar rats the urethral tract has been investigated by histology and scanning electron microscopy using intact tissue and casting techniques. RESULTS: Most striking is the existence of the sinusoids in the spongious tissues in the pelvic urethra into a system of two perpendicular layers of parallel sinusoids. In the spongious tissues of the penile corpus spongiosum the same organization can be found although less prominent. Smooth muscle cells are very unequally present along the urethral tract. In its pelvic part they do not form a continuous layer around the spongious tissue and compared to the distal part they appear proximally more abundant. In the bulbal part of the corpus spongiosum the smooth muscles form a massive sac around the spongious tissue. In the corpus spongiosum in the penile shaft they are absent. The smooth muscle cells are separated from the striated urethral muscle by a very thin layer of connective tissue, in the penile bulb a prominent tunica albuginea separates them from the striated penile muscles. In the spongious tissues of the pelvic urethra and the penile bulb large amounts of compound urethral glands are present. Their ducts open into the respective lumen. Helicine arteries are common in the pelvic urethra, especially in the glandular tissue. They are also normally present in the wing tips of the penile bulb. CONCLUSIONS: The transitional urethra, the urethral diverticle and surrounding spongious tissue are structurally closely related to the other parts, however their microscopical organization is intermediate between the pelvic part of the urethra and the corpus spongiosum. The highly ordered sinusoids in the spongious layers especially in the pelvic part together with a similar organization of the urethral muscle provide a possible basis for a peristaltic driving mechanism, suggesting these structures play a role in the high speed transport of sperms during ejaculation.

Animals↗
PubMed1981

Histology of the canine urethra. I. Morphometry of the female urethra.

Urinary bladders and urethrae were collected from six adult and two juvenile female dogs. Five urethral regions and the neck and body of the bladder were sampled. Volume fractions for connective tissue including elastic fibers, smooth and striated muscle, and epithelium were obtained by projecting section images onto an array of points and computing the number of points overlying a tissue constituent per total points overlying the tissue section. Smooth muscle occupied approximately half the volume of the bladder wall, one-third the volume of the vesical neck, and one-fourth the volume of the proximal urethra. Striated muscle was present in the distal half of the urethra, where the total muscle coat occupied about one-third of the urethral wall volume. Smooth muscle was practically absent in the terminal urethra, where the striated urethralis muscle encircles urethra and vagina in common. Epithelial area and lumen perimeter were not significantly different along the length of the urethra except that urethral epithelium was significantly thicker adjacent to the vesical neck. In terms of histological proportions, the vesical neck was intermediate between the body of the bladder and the proximal urethra.

Aging↗
PubMed1995

Pressure/cross-sectional area relations in the proximal urethra of healthy males. Part 1: Elastance and estimated pressure in the uninstrumented urethra.

The pressure/cross-sectional area relation in the resting urethra during the storage phase was studied in 31 healthy male volunteers aged 23-85 years. Measurements were performed at 5-mm intervals from the bladder neck and beyond the region of high pressure, and the elastance and estimated pressure in the uninstrumented urethra (Po) were calculated at each measurement location. All subjects were further evaluated by means of symptom score, prostatic volume determined by rectal ultrasound, urethral pressure profile, cystometry, and pressure flow. The elastance and Po both varied along the urethra, with significantly higher values of both parameters in the sphincteric region as compared to the prostatic area. A significant positive correlation was found between Po and age in the prostatic parts of the urethra, whereas no correlation could be demonstrated between elastance and age in any part of the urethra. These results indicate that the prostatic parts of the urethra are readily distensible at modest intraluminal pressures as compared to the sphincteric segment, and that the intraluminal pressure required to obtain a given distension of this segment of the urethra seems to increase with age. It is suggested that the technique may prove of value in the elucidation of pathophysiological mechanisms related to benign prostatic hyperplasia, and that the technique may bring new insight into the mode of action of various treatment modalities for this disease.

Adult↗
PubMed1981

Histology of the canine urethra II. Morphometry of the male pelvic urethra.

Urinary bladders and pelvic urethrae were collected from six adult and two juvenile male dogs. Within two vesical and six urethral sampling regions, volume densities were estimated for smooth and striated muscle, connective tissue and elastic fibers, stratum cavernosum, luminal epithelium, and prostate. The neck had significantly less smooth muscle and more connective tissue than the body of the bladder. In the prostatic urethra, smooth muscle was associated principally with trabeculae surrounding prostate lobules. Smooth muscle was sparse superficially in the prostatic capsule and practically absent in relation to the mid-prostatic urethra. Thus there was no mechanism for active closure of the middle prostatic urethra, and elastic fiber density was correspondingly high in this region. The smooth muscle sphincter needed to maintain urinary continuence and prevent semen reflux was primarily the vesical neck. Caudal to the body of the prostate, striated muscle comprised more than 40% of the urethral wall. Juvenile and adult postprostatic urethrae were similar except for a decreased quantity of stratum cavernosum in the pups.

Aging↗
PubMed1990

Mechanical properties of the urethra in healthy and stress incontinent females: dynamic measurements in the resting urethra.

The relationship between pressure and cross-sectional area in the resting urethra during its inflation and deflation was examined in 30 healthy females and in 30 patients with genuine stress incontinence (GSI). Measurements were performed at the bladder neck, in the high-pressure zone and distally in the urethra. The mechanical properties of the urethra were found to vary significantly as a function of time after induction of a cross-sectional area (stress episode) in both groups of women. The pattern of response of the urethra showed significant differences between normals and GSI particularly during dynamic conditions. Our results indicate that mechanical laxity of the urethra at the bladder neck and midurethrally especially at dynamic events (stress episodes) is of pathophysiological importance in GSI.

Adult↗
PubMed1996

Endoluminal ultrasound of the urethra: a new modality for cross-sectional imaging of the urethra?

Endoluminal ultrasound (ELUS) with high-frequency transducers is a new technique for imaging tubular structures. In combination with a rotating mirror, 360 degrees cross-sectional images of the wall can be obtained. Because of the high frequency, the axial resolution is much higher and thus more detail can be seen. In the study reported in this article, ELUS was performed to image the wall of the female pig urethra to see whether cross-sectional images obtained by ELUS could be correlated with anatomic cross sections of the urethra. Commercially available transducers with a frequency of 30 and 20 MHz were used, the latter having the best suitable frequency for this procedure. The images were of high quality and the different anatomic layers could be clearly visualized. The mucosa/submucosa, the external sphincter, and the surrounding serosa were all identifiable. The correct interpretation was also confirmed by histological cross-section study. We believe that endoluminal ultrasound is a very promising technique for imaging the urethra. Further studies need to be conducted to improve the catheters for urological use and to develop the clinical usefulness of this technique.

Animals↗
PubMed1982

Vaginal urethra, clitoral hypertrophy and accessory phallic urethra: a rare syndrome of female pseudohermaphroditism.

The rare syndrome of idiopathic female pseudohermaphroditism with vaginal urethra, clitoral hypertrophy and accessory phallic urethra is commonly associated with urinary tract obstruction. We report a new case and discuss the characteristic features. The embryogenesis of this condition seems to involve complex interactions between the müllerian duct and urogenital sinus rather than hormonal causes. Treatment is aimed at correcting the masculinized appearance of the genitalia and relieving the frequently present urinary obstruction.

Abnormalities, Multiple↗
PubMed1978

Reappraisal of the sympathetic role in the sphincteric urethra. Denervation supersensitivity of the urethra of the chronic neurogenic bladder to alpha-adrenergic drugs.

The response of urethral pressure to administration of an alpha-stimulant was compared between a group of eight patients with chronic neurogenic bladders as evidenced by positive denervation supersensitivity to parasympathomimetic bethanechol chloride and a group of ten control patients. A supersensitive response to administration of an alpha-stimulant with a rise of maximum urethral pressure, 10 mm Hg or more above the control urethral pressure, was uniformly observed in the urethra of patients with chronically denervated bladders. Our results appear to add pharmacologic evidence of alpha-adrenergic predominance over the parasympathetic in the urethra which is believed to be innervated dually in the recently envolving new concept.

Adolescent↗
PubMed1984

[The striated sphincter of the urethra. 2: Specific methods for studying the striated sphincter of the urethra].

Radiology and electromyography of the lower urinary tract are specific techniques for exploration of the urethral rhabdosphincter. Retrograde and mictional urethrography provide data on the extent of the membranous urethra. In the presence of rhabdosphincter lesions a mictional urethrogram is often sufficient to establish a diagnosis from the direct and indirect signs of obstruction it supplies. A retrograde urethrography examination can be added validly to the previous exploration to improve precise definition of sclerosis: in contrast it is indispensable when miction is impossible. Differential diagnosis between spasm and stenosis of striated and dyssynergy of smooth muscle sphincter is by pharmacologic tests. Radiologic study of sphincter contraction is generally by cineradiography with arrest of miction. Results are limited, however, when compared with those of a radiodynamic study: the latter supplies information on the functioning of the para- and peri-urethral rhabdosphincter, and allows measurement of contraction. The electromyogram, with its different practical technical modalities, provides details of the urethral rhabdosphincter. The contact electromyogram gives quantitative data but fails to diagnose a neurological lesion. It analyzes behavior of the sphincter in its para-urethral part and can localize its diaphragmatic portion; dynamic electric profiles are of little reliability, in contrast to static profiles which quantify electric activity at all points in the urethra during the same contraction. The standard percutaneous needle electromyography examination provides qualitative data on the peri-urethral rhabdosphincter, but lacks precision as to the region explored, while qualitative information on the para-urethral sphincter requires the use of an endo-urethral approach. A difference in potential between para- and peri-urethral musculature has been demonstrated a fact confirmed by anatomical findings in Goslings study. In normal subjects, the rhabdosphincter differs from other skeletal muscles by its constant activity except during miction; potentials in children differ from those in adults by their duration. In lower motor neurone disease signs of denervation appear after several weeks, while in upper motor neurone affections the potentials are normal but nociceptive and bulbocavernous stimuli provoke bursts of hyperactivity which reappear very shortly after the paraplegia. Striated muscle fibrosis provokes peripheral signs with persistence of regions of increased reflexes. Tests of responses to stimuli provide important information enabling the site of the neurogenic lesion to be determined.

Electromyography↗
PubMedDate not supplied

[Borderline between the normal and the pathological in the radiological diagnosis of the posterior male urethra and female urethra in childhood].

The authors, with the support of a large case report, point out several varieties of the standard urethrography of a normal urethra and the correlations between macroscopic anatomy, radiologic anatomy and physiology. They stress the importance of a good knowledge of the urethral anatomy and of the urethrographic physiology in order to avoid considering as pathologic a really normal radiologic finding.

Age Factors↗