The urinary meatus (, ; : meati or meatuses), also known as the external urethral orifice, is the opening of the

penis A penis (; : penises or penes) is a sex organ through which male and hermaphrodite animals expel semen during copulation (zoology), copulation, and through which male placental mammals and marsupials also Urination, urinate. The term ''pen ...

vulva In mammals, the vulva (: vulvas or vulvae) comprises mostly external, visible structures of the female sex organ, genitalia leading into the interior of the female reproductive tract. For humans, it includes the mons pubis, labia majora, lab ...

where

urine Urine is a liquid by-product of metabolism in humans and many other animals. In placental mammals, urine flows from the Kidney (vertebrates), kidneys through the ureters to the urinary bladder and exits the urethra through the penile meatus (mal ...

exits the

urethra The urethra (: urethras or urethrae) is the tube that connects the urinary bladder to the urinary meatus, through which Placentalia, placental mammals Urination, urinate and Ejaculation, ejaculate. The external urethral sphincter is a striated ...

during

urination Urination is the release of urine from the bladder through the urethra in Placentalia, placental mammals, or through the cloaca in other vertebrates. It is the urinary system's form of excretion. It is also known medically as micturition, v ...

. It is also where

semen Semen, also known as seminal fluid, is a bodily fluid that contains spermatozoon, spermatozoa which is secreted by the male gonads (sexual glands) and other sexual organs of male or hermaphrodite, hermaphroditic animals. In humans and placen ...

exits during male

ejaculation Ejaculation is the discharge of semen (the ''ejaculate''; normally containing sperm) from the penis through the urethra. It is the final stage and natural objective of male sexual stimulation, and an essential component of natural conception. ...

, and other fluids during

female ejaculation Female ejaculation is characterized as an expulsion of fluid from the Skene's gland at the lower end of the urethra during or before an orgasm. It is also known colloquially as squirting or gushing, although research indicates that female ejacu ...

. The meatus has varying degrees of sensitivity to touch.

In human males

The male external urethral orifice is the external opening of the urethra, normally located at the tip of the

glans penis In male human anatomy, the glans penis or penile glans, commonly referred to as the glans, (; from Latin ''glans'' meaning "acorn") is the bulbous structure at the Anatomical terms of location#Proximal and distal, distal end of the human penis ...

, at its junction with the

frenular delta The frenulum of the penis, often known simply as the frenulum (from ) or frenum, is a thin elastic strip of tissue on the underside of the glans and the neck of the human penis. In men who are not circumcised, it also connects the foreskin to the ...

. It presents as a vertical slit, and continues longitudinally along the front aspect of the glans, which facilitates

micturition Urination is the release of urine from the bladder through the urethra in placental mammals, or through the cloaca in other vertebrates. It is the urinary system's form of excretion. It is also known medically as micturition, voiding, ures ...

. 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 pelvic cavity, pelvis. The main male sex organs are the hu ...

In human females

The female external urethral orifice is where urine exits the

during

. It is located about behind the

clitoris In amniotes, the clitoris ( or ; : clitorises or clitorides) is a female sex organ. In humans, it is the vulva's most erogenous zone, erogenous area and generally the primary anatomical source of female Human sexuality, sexual pleasure. Th ...

and immediately in front of the vaginal opening in the

vulval vestibule The vulval vestibule (also known as the vulvar vestibule or vestibule of vagina) is the part of the vulva between the labia minora. At the innermost part are the vaginal introitus and urinary meatus. The Bartholin's and Skene's glands each ha ...

. 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 plane, transverse and coronal plane, coronal planes. The plane may be in ...

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 or paraurethral glands) are two glands located towards the lower end of the urethra. The glands are surrounded by tissue that swells with ...

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"), sexual climax, or simply climax, is the sudden release of accumulated sexual excitement during the sexual response cycle, characterized by intense sexual pleasure resulting in rhythmic, involu ...

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.

Clinical significance

Congenital disorder A birth defect is an abnormal condition that is present at childbirth, birth, regardless of its cause. Birth defects may result in disability, disabilities that may be physical disability, physical, intellectual disability, intellectual, or dev ...

s of the meatus, in the male, include

epispadias Epispadias is a birth defect in which the urethra fails to fully develop, resulting in urine leaving the body from an abnormal site. In males, this may be an opening on the upper aspect of the penis, and in females when the urethra develops too ...

(the misplacement to the upper aspect) and

hypospadias Hypospadias is a common malformation in fetal development of the penis in which the urethra does not open from its usual location on the head of the penis. It is the second-most common birth defect of the male reproductive system, affecting about ...

(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 meatus , thus constricting the opening through which urine leaves the body from the urinary bladder. Symptoms and signs * Visible narrow opening a ...

), 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 stones Kidney stone disease (known as nephrolithiasis, renal calculus disease, or urolithiasis) is a crystallopathy and occurs when there are too many minerals in the urine and not enough liquid or hydration. This imbalance causes tiny pieces of cr ...

, 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 ...

s ( lithiasis).

Notes

References