The labia minora (Latin for 'smaller lips', singular: ''labium minus'', 'smaller lip'), also known as the inner labia, inner lips, vaginal lips or nymphae are two flaps of skin on either side of the

human Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, cultu ...

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 ...

l opening in the

vulva The vulva (plural: vulvas or vulvae; derived from Latin for wrapper or covering) consists of the external female sex organs. The vulva includes the mons pubis (or mons veneris), labia majora, labia minora, clitoris, vestibular bulbs, vulv ...

, situated between the

labia majora The labia majora (singular: ''labium majus'') are two prominent longitudinal cutaneous folds that extend downward and backward from the mons pubis to the perineum. Together with the labia minora they form the labia of the vulva. The labia majo ...

(Latin for 'larger lips'; also called outer labia, or outer lips). The labia minora vary widely in size, color and shape from individual to individual. The

labia The labia are part of the female genitalia; they are the major externally visible portions of the vulva. In humans, there are two pairs of labia: the ''labia majora'' (or the outer labia) are larger and thicker, while the '' labia minora'' are fo ...

minora are homologous to the male

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 c ...

l surface of the penis.

Structure and functioning

The labia minora extend from the clitoris obliquely downward, laterally, and backward on either side of 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 ...

, ending between the bottom of the vulval vestibule and the labia majora. The posterior ends (bottom) of the labia minora are usually joined across the middle line by a flap of skin, named the

frenulum of labia minora The frenulum of labia minora (''fourchette'' or ''posterior commissure of the labia minora'') is a frenulum where the labia minora meet posteriorly. Pathology The fourchette may be torn during delivery due to the sudden stretching of the vulva ...

or fourchette. On the front, each lip forks dividing into two portions surrounding the clitoris. The upper part of each lip passes above the clitoris to meet the upper part of the other lip—which will often be a little larger or smaller—forming a fold which overhangs the

glans clitoridis 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 of ...

(clitoral tip or head); this fold is named the

clitoral hood In the female human body, the clitoral hood (also called preputium clitoridis and clitoral prepuce) is a fold of skin that surrounds and protects the glans of the clitoris; it also covers the external shaft of the clitoris, develops as part of th ...

. The lower part passes beneath the glans clitoridis and becomes united to its under surface, forming, with the inner lip of the opposite side, the ''frenulum clitoridis''. Vulva labeled english

The clitoral hood, analogously to the

foreskin In male human anatomy, the foreskin, also known as the prepuce, is the double-layered fold of skin, mucosal and muscular tissue at the distal end of the human penis that covers the glans and the urinary meatus. The foreskin is attached to the ...

of the

penis A penis (plural ''penises'' or ''penes'' () is the primary sexual organ that male animals use to inseminate females (or hermaphrodites) during copulation. Such organs occur in many animals, both vertebrate and invertebrate, but males d ...

in men and also termed, like the latter, by the Latin word '' prepuce'', serves to cover most of the time the shaft and sometimes the glans (which is very sensitive to the touch) to protect the clitoris from mechanical irritation and from dryness. Yet the hood is movable and can slide during

clitoral erection Clitoral erection is a physiological phenomenon where the clitoris becomes enlarged and firm. Clitoral erection is the result of a complex interaction of psychological, neural, vascular, and endocrine factors, and is usually, though not exclu ...

or be pulled upwards a little for greater exposure of the clitoris to sexual stimulation. The frenulum (Latin for ''little bridle'') is an elastic band of tissue attached by its one end to the clitoral shaft and glans and by its other end to the prepuce. It allows two-way shifting of the clitoral hood: firstly, it can extend to let the hood be moved upwards to expose the glans for stimulation or hygienic cleansing, and secondly, it contracts to pull the hood back to protect it.

Histology

On the opposed surfaces of the labia minora are numerous

sebaceous gland A sebaceous gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals. In humans, sebaceous glands occur in the greatest nu ...

s not associated with hair follicles. They are lined by stratified squamous epithelium on those surfaces.Manual of Obstetrics. (3rd ed.). Elsevier. pp. 1-16. . Like the whole area of the vulval vestibule, the mucus secreted by those glands protects the labia from dryness and mechanical irritation.

Variation

Being thinner than the outer labia, the inner labia can be also more narrow than the former, or wider than labia majora, thus protruding in the

pudendal cleft The vulva (plural: vulvas or vulvae; derived from Latin for wrapper or covering) consists of the external female sex organs. The vulva includes the mons pubis (or mons veneris), labia majora, labia minora, clitoris, vestibular bulbs, vulval ...

and making the term ''minora'' (Latin for smaller) essentially inapplicable in these cases. They can also be smooth or frilled, the latter being more typical of longer or wider inner labia. From 2003 to 2004, researchers from the Department of Gynaecology, Elizabeth Garret Anderson Hospital in London, measured the labia and other genital structures of 50 women from the age of 18 to 50, with a mean age of 35.6. The study has since been criticized for its "small and homogenous sample group" consisting primarily of white women. The results were: Due to the frequent portrayal of the pudendal cleft without protrusion in art and pornography, there has been a rise in the popularity of

labiaplasty Labiaplasty (also known as labioplasty, labia minora reduction, and labial reduction) is a plastic surgery procedure for altering the labia minora (inner labia) and the labia majora (outer labia), the folds of skin surrounding the human vulva. T ...

, surgery to alter the labia—usually, to make them smaller. On the other hand, there is an opposite movement of labia stretching. Its proponents stress the beauty of long labia and their positive role in sexual stimulation of both partners.

Labiaplasty Labiaplasty (also known as labioplasty, labia minora reduction, and labial reduction) is a plastic surgery procedure for altering the labia minora (inner labia) and the labia majora (outer labia), the folds of skin surrounding the human vulva. T ...

is also sometimes sought by women who have asymmetrical labia minora to adjust the shape of the structures towards identical size. Labia stretching has traditionally been practised in some African nations in the East and South and the South Pacific.Robert Suggs, Marquesan Sexual Behavior ew York: Harcourt, Brace and World, 1966 pp. 39–42

Functioning

The inner lips serve to protect from mechanical irritation, dryness and infections of the highly sensitive area of the

with vaginal and urethral openings in it between them. During vaginal sexual intercourse they may contribute to stimulation of the whole vestibule area, the clitoris and the vagina of the woman and the penis of her partner. Stimulation of the clitoris may occur through tension of the clitoral hood and its frenulum by inner labia pulling at them. During sexual arousal they are lubricated by the mucus secreted in the vagina and around it to make penetration painless and protect them from irritation. As the female external urethral opening (meatus) is also situated between labia minora, they may play a role in guiding the stream of the urine during female urination.

Medical conditions

Being very sensitive by their structure to any irritation, and situated in the excretion area where traces of urine,

vaginal discharge Vaginal discharge is a mixture of liquid, cells, and bacteria that lubricate and protect the vagina. This mixture is constantly produced by the cells of the vagina and cervix, and it exits the body through the vaginal opening. The composition, amou ...

smegma Smegma (Ancient Greek σμῆγμα : ''smēgma'') is a combination of shed skin cells, skin oils, and moisture. It occurs in both male and female mammalian genitalia. In females, it collects around the clitoris and in the folds of the labia ...

and even feces may be present, the inner lips may be susceptible to inflammatory infections of the vulva such as vulvitis. The likelihood of inflammation may be reduced through appropriate regular hygienic cleansing of the whole vulval vestibule, using water and medically tested cleansing agents designed for vulvas. To avoid contamination of the vulva with fecal bacteria, it is recommended that the vulva is washed only from front to back, from

mons pubis In human anatomy, and in mammals in general, the ''mons pubis'' or pubic mound (also known simply as the mons, and known specifically in females as the ''mons Venus'' or ''mons veneris'') is a rounded mass of fatty tissue found over the pubic sym ...

to the

perineum The perineum in humans is the space between the anus and scrotum in the male, or between the anus and the vulva in the female. The perineum is the region of the body between the pubic symphysis (pubic arch) and the coccyx (tail bone), includi ...

and anus. Apart from water and special liquid cleansing agents (lotions), there are commercially available

wet wipe A wet wipe, also known as a wet towel or a moist towelette, disposable wipe, disinfecting wipe, or a baby wipe (in specific circumstances) is a small to medium-sized moistened piece of plastic or cloth that either comes folded and individually ...

s for female intimate hygiene. Some women wipe the vulval vestibule dry with toilet tissue after urination to avoid irritation and infections from residual drops of the urine in the area. However, incorrect choice of cleansing agents, or their incorrect application, may itself cause labial irritation and require medical attention. Over-vigorous rubbing of the labia of little girls while washing, combined with the lack of

estrogen Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal ac ...

in their bodies, may lead to the mostly pediatric condition known as labial fusion. If fused labia prevent urination, urine may accumulate and cause pain and inflammation. In adult females, irritation of the area may be caused by wearing too-tight underwear (especially where wider inner labia protrude in the pudendal cleft); while

G-string A G-string is a type of thong, a narrow piece of fabric, leather, or satin that covers or holds the genitals, passes between the buttocks, and is attached to a waistband around the hips. A G-string can be worn both by men and by women. It may ...

s, which rub against the labia during body movements, may cause irritation or lead to infection from bacteria transferred from either the external environment or the anus.

Additional images

File:Illu repdt female.jpg, Organs of the female reproductive system. File:Vulva and shaved pubic area.jpg, Vulva without pubic hair. File:Clitoris outer anatomy.png, Outer anatomy of clitoris. File:Hairy vulva of a young woman 2.jpg, Vulva with pubic hair.

References

External links

{{DEFAULTSORT:Labia Minora Mammal female reproductive system sn:Hwabvu hutete de:Schamlippe#Die kleinen (inneren) Schamlippen pl:Wargi sromowe mniejsze