urination

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urination

 [u″rĭ-na´shun]
the discharge of urine from the bladder; urine from the kidneys is passed in spurts every few seconds along the ureters to the bladder, where it collects and later is passed to the outside via the urethra. Called also micturition and voiding.

The Urinary Process. Urination is a complex process controlled by muscles of the bladder and sphincter mechanism and by modulatory centers in the central and peripheral nervous systems. The detrusor muscle is a complex meshwork of interlaced smooth muscle bundles that contract in a way that squeezes urine from the bladder vesicle. The sphincter mechanism consists of smooth muscle in the bladder neck and proximal urethra, a striated muscle sphincter consisting of slow twitch muscle fibers in the urethral wall, and periurethral muscles that are a component of the pelvic floor muscles. The detrusor relaxes during bladder filling to accommodate increasing volumes at a low pressure, and the sphincter remains tightly closed. During urination, the detrusor contracts and the sphincter mechanism relaxes, allowing smooth outflow of urine.



As the bladder fills, modulatory centers in the brain prevent the occurrence of contractions. Meanwhile, the sphincter mechanism remains closed under autonomic and somatic nervous system control. During urination, the inhibition of contractions is removed and a reflex originates in the pontine micturition center. That causes the detrusor muscle to contract and the sphincter mechanism to relax. The location of the final output of central nervous system impulses to and from the bladder and sphincter is the sacral micturition center, located in spinal segments 2, 3, and 4, which must be intact for contraction to occur. Injury to the pontine micturition center will compromise the smooth coordination between sphincter mechanism and detrusor muscle, and injury to the brain will affect the volitional control of urine (bladder stability). See also urinary incontinence.

u·ri·na·tion

(yūr'i-nā'shŭn),
The passing of urine.
Synonym(s): miction, micturition (1) , uresis

u·ri·na·tion

(yūr'i-nā'shŭn)
The passing of urine.
Synonym(s): miction, micturition (1) , uresis.

Patient discussion about urination

Q. protien in urine what are the causes and preventions

A.

Q. How you stop urinating frequently? I don't have any conditions that make me urinate often. I simply drink lots of water... Is there some trick I can employ so that I can still drink lots of water but not have to go to the bathroom so frequently?

A. I only drink water and green tea, Thanks.

Q. Today doctor removed my stunt of kidney. It inflamate while urination.. till How long i will feel like this?

A. You should consult your doctor, since instruments in the kidney and urinary tracts can cause infections (even after removing them), that may cause symptoms like you describe.

More discussions about urination
References in periodicals archive ?
Effectuer des mictions completes en etant detendue ;
McGrath ends the poem irreverently, with strong alliteration and a comically heavy-handed pun, as he refers to Papa pissing: "The force of my miction makes the mighty Gulf Stream." McGrath's use of the obsolete word may derive from an obscure reference in Joyce's Finnegan's Wake where it is listed among the names given in the "untitled mamafesta" of "Annah the Allmaziful" (104): "Chee Chee Cheels on their China Miction" (106).
* Must rapidly absorb urine during the miction and subsequently transfer the urine within the absorbent structure.
The striated muscles of the pelvic floor play an important role in miction, defecation and sexual function.
Al Bayane : Quels sont les dangers du retardement de la miction ?