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The urinary meatus, (, ) also known as the external urethral orifice, is the opening of the
urethra The urethra (from Greek οὐρήθρα – ''ourḗthrā'') is a tube that connects the urinary bladder to the urinary meatus for the removal of urine from the body of both females and males. In human females and other primates, the urethra ...
. It is the point where
urine Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excreted from the body through the urethra. Cellul ...
exits the urethra in both sexes and where
semen Semen, also known as seminal fluid, is an organic bodily fluid created to contain spermatozoa. It is secreted by the gonads (sexual glands) and other sexual organs of male or hermaphroditic animals and can fertilize the female ovum. Semen i ...
exits the urethra in males. The meatus has varying degrees of sensitivity to touch. The meatus is located on the glans of the penis or in the vulval vestibule.


In human males

The male external urethral orifice is the external opening or urinary meatus, normally located at the tip of the
glans penis In male human anatomy, the glans penis, commonly referred to as the glans, is the bulbous structure at the distal end of the human penis that is the human male's most sensitive erogenous zone and their primary anatomical source of sexual p ...
, at its junction with the frenular delta. It presents as a vertical slit, possibly bounded on either side by two small labia-like projections, and continues longitudinally along the front aspect of the glans, which facilitates the flow of urine
micturition Urination, also known as micturition, is the release of urine from the urinary bladder through the urethra to the outside of the body. It is the urinary system's form of excretion. It is also known medically as micturition, voiding, uresis, ...
. In some cases, the opening may be more rounded. This can occur naturally or may also occur as a side effect of excessive skin removal during circumcision. The meatus is a sensitive part of the male reproductive system.


In human females

The female external urethral orifice is the external opening of the
urethra The urethra (from Greek οὐρήθρα – ''ourḗthrā'') is a tube that connects the urinary bladder to the urinary meatus for the removal of urine from the body of both females and males. In human females and other primates, the urethra ...
, from which
urine Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excreted from the body through the urethra. Cellul ...
is ejected during
urination Urination, also known as micturition, is the release of urine from the urinary bladder through the urethra to the outside of the body. It is the urinary system's form of excretion. It is also known medically as micturition, voiding, uresis, ...
. It is located about behind the
clitoris The clitoris ( or ) is a female sex organ present in mammals, ostriches and a limited number of other animals. In humans, the visible portion – the glans – is at the front junction of the labia minora (inner lips), above the o ...
and immediately in front of the
vagina In mammals, the vagina is the elastic, muscular part of the female genital tract. In humans, it extends from the vestibule to the cervix. The outer vaginal opening is normally partly covered by a thin layer of mucosal tissue called the hy ...
in the vulval vestibule. It usually assumes the form of a short, sagittal cleft with slightly raised margins. To its left and right are the openings of the Skene's glands. Some evidence exists to suggest that the clitoral-urinary meatus distance (CUMD) in human females relates to the ease with which the female may achieve
orgasm Orgasm (from Greek , ; "excitement, swelling") or sexual climax is the sudden discharge of accumulated sexual excitement during the sexual response cycle, resulting in rhythmic, involuntary muscular contractions in the pelvic region char ...
through penetrative sex. Orgasm from penetration alone is observed to be more likely as CUMD decreases. Evidence also suggests that decreased distance from the vaginal opening to the urethral meatus is associated with recurrent post-coital urinary tract infections. Surgical repositioning of the distal urethra to prevent recurrent post-coital urinary tract infections has been employed with some success by Russian physicians.


In other mammals

Unlike most other mammals (including human), female
spotted hyena The spotted hyena (''Crocuta crocuta''), also known as the laughing hyena, is a hyena species, currently classed as the sole extant member of the genus ''Crocuta'', native to sub-Saharan Africa. It is listed as being of least concern by the I ...
s have a urinary meatus that is located on the
clitoral glans The clitoris ( or ) is a female sex organ present in mammals, ostriches and a limited number of other animals. In humans, the visible portion – the glans – is at the front junction of the labia minora (inner lips), above the o ...
.


Clinical significance

Congenital disorder A birth defect, also known as a congenital disorder, is an abnormal condition that is present at birth regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities can r ...
s of the meatus, in the male, include
epispadias An epispadias is a rare type of malformation in which the urethra ends, in males, in an opening on the upper aspect of the penis, and in females when the urethra develops too far anteriorly. It occurs in around 1 in 120,000 male and 1 in 500,000 ...
(the misplacement to the upper aspect) and
hypospadias Hypospadias is a common variation in fetal development of the penis in which the urethra does not open from its usual location in the head of the penis. It is the second-most common birth abnormality of the male reproductive system, affecting abo ...
(the misplacement to the underside of the penis). A congenital misshaping can result in its narrowing ( meatal stenosis), causing a partial or total urinary blockage or the bifurcation of the urinary stream. A urethral blockage can also be caused by foreign material,
kidney The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; blo ...
stones, or bladder stones ( lithiasis).


Additional images

Male urinary meatus.jpg, The male urinary meatus viewed externally Skenes gland.jpg, The female urinary meatus viewed externally, with surrounding structures labelled


See also

* Urogenital opening


Notes


References

{{Authority control Urinary system Urethra