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 con ...
. 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 excretion, excreted from the body through the urethra.
Cel ...
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
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 ...
or in the
vulval vestibule
The vulval vestibule (or vulvar vestibule or vestibule of vagina) is a part of the vulva between the labia minora into which the urinary meatus (urethral opening) and the vaginal opening open. Its edge is marked by Hart's line. It represents the ...
.
In human males
![Male anatomy en](https://upload.wikimedia.org/wikipedia/commons/d/d1/Male_anatomy_en.svg)
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
The glans (, plural "glandes" ; from the Latin word for "acorn") is a vascular structure located at the tip of the penis in male mammals or a homologous genital structure of the clitoris in female mammals.
Structure
The exterior structure ...
, 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
The male reproductive system consists of a number of sex organs that play a role in the process of human reproduction. These organs are located on the outside of the body and within the pelvis.
The main male sex organs are the penis and the tes ...
.
In human females
![Female anatomy with g-spot-en](https://upload.wikimedia.org/wikipedia/commons/0/0d/Female_anatomy_with_g-spot-en.svg)
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 con ...
, 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 excretion, excreted from the body through the urethra.
Cel ...
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 ope ...
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 hymen ...
in the
vulval vestibule
The vulval vestibule (or vulvar vestibule or vestibule of vagina) is a part of the vulva between the labia minora into which the urinary meatus (urethral opening) and the vaginal opening open. Its edge is marked by Hart's line. It represents the ...
. It usually assumes the form of a short,
sagittal
The sagittal plane (; also known as the longitudinal plane) is an anatomical plane that divides the body into right and left sections. It is perpendicular to the transverse and coronal planes. The plane may be in the center of the body and divi ...
cleft with slightly raised margins. To its left and right are the openings of the
Skene's gland
In female human anatomy, Skene's glands or the Skene glands ( , also known as the lesser vestibular glands, paraurethral glands) are glands located around the lower end of the urethra. The glands are surrounded by tissue that swells with blood ...
s.
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 charac ...
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 IUC ...
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 ope ...
.
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 ...
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 abou ...
(the misplacement to the underside of the penis). A congenital misshaping can result in its narrowing (
meatal stenosis
Urethral meatal stenosis is a narrowing (stenosis) of the opening of the urethra at the external urinary meatus, meatus , thus constricting the opening through which urine leaves the body from the urinary bladder.
Symptoms and signs
* Abnormal ...
), 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; blood ...
stones, or
bladder stone
A bladder stone is a stone found in the urinary bladder.
Signs and symptoms
Bladder stones are small mineral deposits that can form in the bladder. In most cases bladder stones develop when the urine becomes very concentrated or when one is d ...
s (
lithiasis
A calculus (plural calculi), often called a stone, is a concretion of material, usually mineral salts, that forms in an organ or duct of the body. Formation of calculi is known as lithiasis (). Stones can cause a number of medical conditions.
So ...
).
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
The urogenital opening is where bodily waste and reproductive fluids are expelled to the environment outside of the body cavity. In some organisms, including birds and many fish, discharge from the urological, digestive, and reproductive systems e ...
Notes
References
{{Authority control
Urinary system
Urethra