Dissection of prostate showing the fibers of the external sphincter surrounding the membranous urethra and partially cradling the inferior portion of the prostate.
The urethral sphincters are two muscles used to control the exit of urine in the urinary bladder through the urethra. The two muscles are either the male or female external urethral sphincter and the internal urethral sphincter. When either of these muscles contracts, the urethra is sealed shut.
The external urethral sphincter originates at the ischiopubic ramus and inserts into the intermeshing muscle fibers from the other side. It is controlled by the deep perineal branch of the pudendal nerve. Activity in the nerve fibers constricts the urethra.
The internal sphincter muscle of urethra: located at the bladder's inferior end and the urethra's proximal end at the junction of the urethra with the urinary bladder. The internal sphincter is a continuation of the detrusor muscle and is made of smooth muscle, therefore it is under involuntary or autonomic control. This is the primary muscle for prohibiting the release of urine.
The female or male external sphincter muscle of urethra (sphincter urethrae): located in the deep perineal pouch, at the bladder's distal inferior end in females, and inferior to the prostate (at the level of the membranous urethra) in males. It is a secondary sphincter to control the flow of urine through the urethra. Unlike the internal sphincter muscle, the external sphincter is made of skeletal muscle, therefore it is under voluntary control of the somatic nervous system.[1]
^Maclean, Allan; Reid, Wendy (2011). "40". In Shaw, Robert (ed.). Gynaecology. Edinburgh New York: Churchill Livingstone/Elsevier. pp. 599–612. ISBN 978-0-7020-3120-5; Access provided by the University of Pittsburgh{{cite book}}: CS1 maint: postscript (link)
and 28 Related for: Urethral sphincters information
The urethralsphincters are two muscles used to control the exit of urine in the urinary bladder through the urethra. The two muscles are either the male...
The internal urethralsphincter is a urethralsphincter muscle which constricts the internal urethral orifice. It is located at the junction of the urethra...
has also reportedly resulted in a complete and permanent loss of urethralsphincter control (urinary incontinence); furthermore such intercourse presents...
particular the millions of precapillary sphincters. Sphincters relax at death, often releasing fluids and faeces. Each sphincter is associated with the lumen (opening)...
ejaculation. The external urethralsphincter is a striated muscle that allows voluntary control over urination. The internal sphincter, formed by the involuntary...
incontinence. It is due to inadequate closure of the bladder outlet by the urethralsphincter. It is the loss of small amounts of urine associated with coughing...
External sphincter muscle of urethra can refer to: external sphincter muscle of male urethra external sphincter muscle of female urethra This disambiguation...
the vulva, including urine (from the urethral opening during urination through control of the external sphincter muscle), sweat (from the apocrine glands)...
bladder Stress incontinence due to "a poorly functioning urethralsphincter muscle (intrinsic sphincter deficiency) or to hypermobility of the bladder neck...
urine along with the internal urethralsphincter which is under control of the autonomic nervous system. The external sphincter muscle prevents urine leakage...
pelvic muscles, including the male or female external urethralsphincter and the external anal sphincter. If damaged, most commonly by childbirth, loss of...
labeled at center left List of homologues of the human reproductive system Urethral gland List of distinct cell types in the adult human body Liebich, Hans-Georg...
complications due to the highly vascular nature of the tissue. The urethralsphincters and its smooth muscle, as well as the neck of the bladder, can be...
urine along with the internal urethralsphincter which is under control of the autonomic nervous system. The external sphincter muscle prevents urine leakage...
the detrusor muscles of the bladder and the male or female external urethralsphincter muscles. In normal lower urinary tract function, these two separate...
detrusor muscle to contract and the internal urethralsphincter to relax. The external urethralsphincter (sphincter urethrae) is under somatic control and...
bladder sphincter. Post-pubertal males (aged 17 to 20 years) who experience repeated episodes of retrograde ejaculation are often diagnosed with urethral stricture...
normally. This is because tamsulosin relaxes the muscles of the urethralsphincters, which are normally closed during ejaculation. Tamsulosin is a selective...
The internal urethral orifice is the opening of the urinary bladder into the urethra. It is usually somewhat crescent-shaped.[citation needed] It is formed...
and contracts during urination to release urine. Related are the urethralsphincter muscles which envelop the urethra to control the flow of urine when...
penile raphe is a visible line or ridge of tissue that runs on the ventral (urethral) side of the human penis beginning from the base of the shaft and ending...
out of the penis, the bladder neck stays shut while the external urethralsphincter is relaxed. These rhythmic contractions are part of the male orgasm...
the two glans wings in the ventral midline. The septum extends from the urethral meatus through the glanular urethra (fossa navicularis) and ends in the...
deferens, and are eventually expelled through the urethra and out of the urethral orifice through muscular contractions. Within the seminiferous tubules...
rhabdos meaning "rod") is a sphincter consisting of striated muscle fibres. The muscle is a part of the external urethralsphincter that continues superiorly...
Global Information