micturition


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Related to micturition: micturition reflex, Micturition syncope, Hycort

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.

mic·tu·ri·tion

(mik'chū-rish'ŭn), Avoid the misspelling/mispronunciation micturation.
1. Synonym(s): urination
2. The desire to urinate.
3. Frequency of urination.
[L. micturio, to desire to make water]

micturition

/mic·tu·ri·tion/ (mik″tu-rĭ´shun) urination.

micturition

See urination.

micturition

Urination; the act of voiding urine.

micturition

 Urination; the process of voiding urine

mic·tu·ri·tion

(mik-chŭr-ish'ŭn)
1. Synonym(s): urination.
2. The desire to urinate.
3. Frequency of urination.
[L. micturio, to desire to make water]

micturition

the release of urine from the body. see BLADDER.

micturition

urination.

micturition disorders
includes neurogenic disorders controlling urination, urinary incontinence from several causes, and behavioral disorders. See also incontinence, urinary bladder, elimination behavior, ectopic ureter and inappropriate micturition (below).
inappropriate micturition
done at the wrong time or place, as dogs or cats urinating in the house or away from a litter tray. See also spraying.
micturition reflex
the sequence of neurological impulses and muscular responses that controls the retention and release of urine.
References in periodicals archive ?
The normal micturition reflex involves switching from inhibition of the voiding reflex and activation of storage reflexes to inhibition of the storage reflexes and activation of the voiding reflex--and back again.
In addition, our aim was to capitalize on the micturition data of patients with preintervention incidents to determine the intraindividual biologic variability and thus predict the proper, complete collection of 24-hour urine for each patient on the basis of their usual rate of micturition.
Honey was said to move the bowels, be an emetic, be nutritious in fevers, an astringent (when old honey was boiled in a leaden pot) and of value with difficult micturition (1.
2, respectively; median increases in the volume of urine voided per micturition were 34, 29, and 14 mL, respectively; and median decreases in the number of incontinence episodes per week were 11.
According to Paine and Byers (1953) classification, a good recovery comprised normal gait, normal or minimal micturition urgency and normal or minimal neurological signs.
The act of micturition involves a complex interplay between the spinal cord, cerebellum, and the pontine micturition center.
OCTOPUSH (ock-t'-push)--the eighth stage of labour in the birthing experience of a parturient octopus [underwater hockey for two teams of eight swimmers with snorkels who 'push' a lead 'squid' around at the bottom of a pool] PISSASPHALT (piss-ass-falt)--a horizontal urinal with a porous bitumen surface installed for the micturition needs of long-haul truck drivers in outback Australia [a form of semi-liquid bitumen]
Although UI is not an inevitable consequence of getting older, age-related physiologic changes of the lower urinary tract may alter the micturition habits and predispose women to UI.
The important areas of the neurologic system that regulate bladder function are the pons (pontine micturition center) and the sacral cord (sacral micturition center).
urethral discharge, burning micturition, itching of genitalia, swelling in groin, genital ulcers, scrotal swelling).
For those with an interest in canine defecation and micturition, this chapter provides absorbing reading.