Labia

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When the rounded thicker labia majora are pulled aside, the labia minora are more visible. The labia minora are vertical folds of skin in the very middle of the vulva. Grosse und kleine Schamlippen.jpg
When the rounded thicker labia majora are pulled aside, the labia minora are more visible. The labia minora are vertical folds of skin in the very middle of the vulva.

The labia are the major externally visible structures of the vulva. In humans and other primates, there are two pairs of labia: the labia majora (outer lips) are large and thick folds of skin that cover the vulva's other parts, while the labia minora (inner lips) are the folds of skin between the outer labia that surround and protect the urethral and vaginal openings, [1] as well as the glans clitoris.

Contents

In other mammals, the labia majora are not present and the labia minora are instead referred to as the labia vulvae . [2] [3] [4]

Etymology

Labium (plural labia) is a Latin-derived term meaning "lip". Labium and its derivatives (including labial, labrum) are used to describe any lip-like structure, but in the English language, labia often specifically refers to parts of the vulva.

Structure

Left: In their resting state, the labia protect the inner areas of the vulva. Right: Spreading the labia apart exposes inner areas of the vulva. A) Anterior commissure of labia majora B) Clitoral hood C) Labia minora D) Labia majora E) Posterior commissure of labia majora F) Clitoral glans G) Inner surface of labia majora H) Vulvar vestibule I) External urethral orifice J) Vaginal orifice K) Fourchette Scheide-labelled.jpg
Left: In their resting state, the labia protect the inner areas of the vulva.
Right: Spreading the labia apart exposes inner areas of the vulva.
A) Anterior commissure of labia majora
B) Clitoral hood
C) Labia minora
D) Labia majora
E) Posterior commissure of labia majora
F) Clitoral glans
G) Inner surface of labia majora
H) Vulvar vestibule
I) External urethral orifice
J) Vaginal orifice
K) Fourchette

The labia majora are lip-like structures consisting mostly of skin and adipose (fatty) tissue, which extend on either side of the vulva to form the pudendal cleft through the middle. They enclose and protect the other tissues of the vulva. The labia majora often have a plump appearance, and are thicker towards the anterior. [5] The anterior junction of the labia majora is called the anterior commissure, which is below the mons pubis and above the clitoris. To the posterior, the labia majora join at the posterior commissure, which is above the perineum and below the frenulum of the labia minora. The grooves between the labia majora and labia minora are known as the interlabial sulci or interlabial folds.

The labia minora are two soft folds of fat-free, hairless skin between the labia majora. They enclose and protect the vulvar vestibule, urethra and vagina. The upper portion of each of the labia minora splits to join both the clitoral glans, and the clitoral hood. The labia minora meet posteriorly at the frenulum of the labia minora (also known as the fourchette), which is a fold of skin below the vaginal orifice. The fourchette is more prominent in younger women, and often recedes after sexual activity [6] and childbirth. [5] When standing or with the legs together, the labia majora usually entirely or partially cover the moist, sensitive inner surfaces of the vulva, which indirectly protects the vagina and urethra, [5] much like the lips protect the mouth. The outer surface of the labia majora is pigmented skin, and develops pubic hair during puberty. The inner surface of the labia majora is smooth, hairless skin, which resembles a mucous membrane, and is only visible when the labia majora and labia minora are drawn apart.

Both the inner and outer surfaces of the labia majora contain sebaceous glands (oil glands), apocrine sweat glands, and eccrine sweat glands. The labia majora have fewer superficial nerve endings than the rest of the vulva, but the skin is highly vascularized. [6] The internal surface of the labia minora is a thin moist skin, with the appearance of a mucous membrane. They contain many sebaceous glands, and occasionally have eccrine sweat glands. The labia minora have many sensory nerve endings, and have a core of erectile tissue. [5]

Labia minora are pronounced differently in different women. This natural variation is completely normal. Depending on the length, the labia minora are visible or completely covered in a standing posture. Labia minora variation.jpg
Labia minora are pronounced differently in different women. This natural variation is completely normal. Depending on the length, the labia minora are visible or completely covered in a standing posture.

Diversity

The color, size, length, and shape of the inner labia can vary extensively from woman to woman. [7] In some women, the labia minora are almost non-existent, and in others, they can be fleshy and protuberant. They can range in color from a light pink to brownish black, [8] and texturally can vary between smooth and very rugose. [9]

Embryonic development and changes over time

The urogenital folds form the labia minora while [10] [11] the labioscrotal swellings become the labia majora. [7] [12]

Illustration of the Tanner scale for females, which is a scale for tracking physical changes that occur during puberty. Progression of pubic hair growth can be seen on the right. Tanner scale-female.svg
Illustration of the Tanner scale for females, which is a scale for tracking physical changes that occur during puberty. Progression of pubic hair growth can be seen on the right.

The genital tissues are greatly influenced by natural fluctuations in hormone levels, which lead to changes in labia size, appearance, and elasticity at various life stages. At birth, the labia minora are well-developed, and the labia majora appear plump due to being exposed to maternal hormones in the womb. The labia majora have the same color as the surrounding skin. Labial adhesions can occur between the ages of 3 months and 2 years, and may make the vulva look flat. These adhesions are not usually a cause for concern, and usually disappear without treatment. Treatment options may include estrogen cream, manual separation with local anesthesia, or surgical separation under sedation. [6]

Aroused labia majora with wrinkles Labia Wrinkles.jpg
Aroused labia majora with wrinkles

During early childhood, the labia majora look flat and smooth because of decreasing levels of body fat, and the diminished effects of maternal hormones. The labia minora become less prominent.

During puberty, increased hormone levels often significantly change the appearance of the labia. The labia minora become more elastic, prominent, and wrinkled. The labia majora regain fat, and begin growing pubic hair close to the pudendal cleft. Hair is initially sparse and straight, but gradually becomes darker, denser, and curlier as growth spreads outward and upward toward the thighs and mons pubis. At the end of puberty, pubic hair will be coarse, curly, and fairly thick. The patch of pubic hair covering the genitals will eventually often form a triangle shape. [8]

By adulthood, the outer surface of the labia majora may be darker than the surrounding skin, and may have wrinkles. During the reproductive years, if a woman delivers a child, the fourchette will flatten. Pregnancy may cause the labia minora to darken in color. [7]

Later in life, the labia majora once again gradually lose fat, becoming flatter and more wrinkled, and pubic hair turns grey. Following menopause, falling hormone levels cause further changes to the labia. The labia minora atrophy, making them become less elastic, and pubic hair on the labia majora becomes more sparse. [6]

Sexual arousal and response

Left: A vulva in the resting, unaroused state. Right: During sexual arousal, the inner and outer labia swell, the labia majora recede slightly, and the vulva becomes lubricated. Female sexual arousal.JPG
Left: A vulva in the resting, unaroused state.
Right: During sexual arousal, the inner and outer labia swell, the labia majora recede slightly, and the vulva becomes lubricated.

The labia are an erogenous zone. In particular, the labia minora are sexually responsive, [13] and sensitivity varies greatly. In some, they are so sensitive that anything other than light touch may be uncomfortable, whereas stimulation may elicit no sexual response in others. The labia may be sexually stimulated as part of masturbation or with a sex partner, such as by fingering or oral sex. Moving the labia minora can also stimulate the extremely sensitive clitoris.

During sexual arousal, the labia majora swell due to increased blood flow to the region, [12] and slightly draw back, [7] revealing the inner labia. The labia minora become engorged with blood, causing them to expand in diameter by two to three times, and darken or redden in color. [12] Because pregnancy and childbirth increase genital vascularity, the inner and outer labia will engorge faster in women who have had children. [12]

After a period of sexual stimulation, the labia minora will become further engorged with blood approximately 30 seconds to 3 minutes before orgasm, [12] causing them to redden further. [12] [14] In those who have had children, the labia majora may also swell significantly during this period, becoming dark red. Continued stimulation can result in an orgasm, and the orgasmic contractions help remove blood trapped in the inner and outer labia, as well as the clitoris and other parts of the vulva, which causes pleasurable orgasmic sensations.

Following orgasm or when no longer sexually aroused, the labia gradually return to their unaroused state. [12] The labia minora return to their original color within 2 minutes, and engorgement dissipates in about 5 to 10 minutes. [8] The labia majora return to their pre-arousal state in approximately 1 hour. [8]

Society and culture

In many cultures and locations all over the world, the labia, as part of the genitalia, are considered private, or intimate parts, whose exposure (especially in public) is governed by fairly strict socio-cultural mores. In many cases, public exposure is limited, and often prohibited by law. [15] [16]

Views on pubic hair differ between people and between cultures. Some women prefer the look or feel of pubic hair, while others may choose to remove some or all of it. Temporary methods of removal include shaving, trimming, waxing, sugaring and depilatory products while permanent hair removal can be accomplished using electrolysis or laser hair removal. [17] In Korea, pubic hair is considered a sign of fertility, leading some women to have pubic hair transplants. [12]

Left: Vulva with pubic hair. Right: Vulva with hair removed by waxing. Brazilian Waxing.jpg
Left: Vulva with pubic hair. Right: Vulva with hair removed by waxing.

Some women are self-conscious about the size, color or asymmetry of their labia. Viewing pornography may influence a woman's view of her genitals. [6] [7] Models in pornography frequently have small or non-existent labia minora, and images are often airbrushed, [7] [17] so pornographic images do not depict the full range of natural variations of the vulva. This can lead viewers of pornography to have unrealistic expectations about how the labia should look. Similar to how some women develop self-esteem issues from comparing their faces and bodies to airbrushed models in magazines, women who compare their vulvas to idealized pornographic images may believe their own labia are abnormal. This can have a negative impact on a woman's life, since genital self-consciousness makes it more difficult to enjoy sexual activity, see a gynecologist, or perform a genital self-examination. [7] Developing an awareness for how much the labia truly differ between individuals may help to overcome this self-consciousness. [17]

In several countries in Africa and Asia, the vulva is routinely altered or removed for reasons related to ideas about tradition, purity, hygiene and aesthetics. Known as female genital mutilation, the procedures include clitoridectomy and so-called "pharaonic circumcision," whereby the inner and outer labia are removed and the vulva is sewn shut. [18] [19] FGM is mostly outlawed around the world, even in countries where the practice is widespread. [20]

Labiaplasty is a controversial plastic surgery procedure that involves the creation or reshaping of the labia. [21] Labia piercing is a cosmetic piercing, usually with a special needle under sterile conditions, of the inner or outer labia. Jewelry is worn in the resulting opening.

Additional images

See also

Related Research Articles

<span class="mw-page-title-main">Clitoris</span> Erectile female sexual organ

In amniotes, the clitoris is a female sex organ. In humans, it is the vulva's most erogenous area and generally the primary anatomical source of female sexual pleasure. The clitoris is a complex structure, and its size and sensitivity can vary. The visible portion, the glans, of the clitoris is typically roughly the size and shape of a pea and is estimated to have at least 8,000 nerve endings.

<span class="mw-page-title-main">Labia majora</span> Folds of skin that contain and protect the vulvas other parts

In primates, and specifically in humans, the labia majora, also known as the outer lips or outer labia, are two prominent longitudinal skin 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.

<span class="mw-page-title-main">Labia minora</span> Flaps of skin on either side of the vaginal opening in the vulva

The labia minora, also known as the inner labia, inner lips, or nymphae, are two flaps of skin that are part of the primate vulva, extending outwards from the inner vaginal and urethral openings to encompass the vestibule. At the glans clitoris, each labium splits, above forming the clitoral hood, and below the frenulum of the clitoris. At the bottom, the labia meet at the labial commissure. The labia minora vary widely in size, color and shape from individual to individual.

<span class="mw-page-title-main">Secondary sex characteristic</span> Features that occur in an organism at sexual maturity

A secondary sex characteristic is a physical characteristic of an organism that is related to or derived from its sex, but not directly part of its reproductive system. In humans, these characteristics typically start to appear during puberty—and include enlarged breasts and widened hips of females, facial hair and Adam's apples on males, and pubic hair on both. In non-human animals, they can start to appear at sexual maturity—and include, for example, the manes of male lions, the bright facial and rump coloration of male mandrills, and horns in many goats and antelopes.

<span class="mw-page-title-main">Clitoral hood</span> Part of the vulva that covers and protects the glans of the clitoris

In female humans and other mammals, the clitoral hood is a fold of skin that surrounds and protects the glans of the clitoris; it also covers the external clitoral shaft, develops as part of the labia minora and is homologous with the foreskin in the male reproductive system. The clitoral hood is composed of mucocutaneous tissues; these tissues are between the mucous membrane and the skin, and they may have immunological importance because they may be a point of entry of mucosal vaccines.

<span class="mw-page-title-main">Mons pubis</span> Rounded mass of fatty tissue found over the pubic symphysis

In human anatomy, and in mammals in general, the mons pubis or pubic mound is a rounded mass of fatty tissue found over the pubic symphysis of the pubic bones.

<span class="mw-page-title-main">Erogenous zone</span> Area of heightened sensitivity of the body, touching which may elicit a sexual response

An erogenous zone is an area of the human body that has heightened sensitivity, the stimulation of which may generate a sexual response such as relaxation, sexual fantasies, sexual arousal, and orgasm.

<span class="mw-page-title-main">Genital piercing</span> Form of body piercing on a part of the genitalia

Genital piercing is a form of body piercing that involves piercing a part of the genitalia, thus creating a suitable place for wearing different types of jewellery. Nevertheless, the term may also be used pars pro toto to indicate all body piercings in the area of the anus, perineum, penis, scrotum, and vulva, including piercings such as anal, guiche, and pubic that do not involve perforation of genitalia. Genital piercings can be done regardless of sex, with various forms of piercings available. The main motive is beautification and individualization; in addition, some piercings enhance sexual pleasure by increasing stimulation. Pre-modern genital piercings is most culturally widespread in Southeast Asia, where it has been part of traditional practice since ancient times. Records of genital piercing are found in the Kama Sutra.

<span class="mw-page-title-main">Female reproductive system</span> Reproductive system of female humans

The human female reproductive system is made up of the internal and external sex organs that function in the reproduction of new offspring. The reproductive system is immature at birth and develops at puberty to be able to release matured ova from the ovaries, facilitate their fertilization, and create a protective environment for the developing fetus during pregnancy. The female reproductive tract is made of several connected internal sex organs—the vagina, uterus, and fallopian tubes—and is prone to infections. The vagina allows for sexual intercourse, and is connected to the uterus at the cervix. The uterus accommodates the embryo by developing the uterine lining.

<span class="mw-page-title-main">Fourchette piercing</span> Female genital piercing

A fourchette piercing is a female genital piercing. It is a piercing done at the rear rim of the vulva, in the area of frenulum of labia minora. Many women do not have a pinchable flap of skin in the area, and are not suited for this piercing. Otherwise, placement and piercing tends to be relatively easy.

Vulvitis is inflammation of the vulva, the external female mammalian genitalia that include the labia majora, labia minora, clitoris, and introitus. It may co-occur as vulvovaginitis with vaginitis, inflammation of the vagina, and may have infectious or non-infectious causes. The warm and moist conditions of the vulva make it easily affected. Vulvitis is prone to occur in any female especially those who have certain sensitivities, infections, allergies, or diseases that make them likely to have vulvitis. Postmenopausal women and prepubescent girls are more prone to be affected by it, as compared to women in their menstruation period. It is so because they have low estrogen levels which makes their vulvar tissue thin and dry. Women having diabetes are also prone to be affected by vulvitis due to the high sugar content in their cells, increasing their vulnerability. Vulvitis is not a disease, it is just an inflammation caused by an infection, allergy or injury. Vulvitis may also be symptom of any sexually transmitted infection or a fungal infection.

<span class="mw-page-title-main">Fingering (sexual act)</span> Use of fingers to sexually stimulate

Fingering is sexual stimulation of the vulva or vagina by using the fingers. Vaginal fingering is legally and medically called digital penetration or digital penetration of the vagina. The term "digital" takes its significance from the English word 'digit', which refers to a finger, thumb, or toe. Fingering may also include the use of fingers to stimulate the anus.

<span class="mw-page-title-main">Labiaplasty</span> Plastic surgery procedure for altering the labia minora

Labiaplasty is a plastic surgery procedure for creating or altering the labia minora and the labia majora, the folds of skin of the human vulva. It is a type of vulvoplasty. There are two main categories of women seeking cosmetic genital surgery: those with conditions such as intersex, and those with no underlying condition who experience physical discomfort or wish to alter the appearance of their vulvas because they believe they do not fall within a normal range.

<span class="mw-page-title-main">Labia piercing</span> Female genital piercing

Labia piercings are a type of female genital piercing. This piercing can be placed either through the labia minora or the labia majora. They are one of the simpler and more common genital piercings performed on vulvas, and are often pierced in symmetrical pairs. Like all genital piercings, depending on jewellery and placement, they may provide additional stimulation to one or both partners during sexual intercourse.

<span class="mw-page-title-main">Vulval vestibule</span> Part of the vulva that contains the openings

The vulval vestibule 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 have two openings to the vestibule on the inside. The outer edge, marked by a coloration difference in the tissues, is called Hart's line, named after David Berry Hart.

<span class="mw-page-title-main">Corpus cavernosum of clitoris</span> One of a pair of regions in the clitoris that contain the blood during erection

The corpus cavernosum of the clitoris is one of a pair of sponge-like regions of erectile tissue that engorge with blood during an erection. This is homologous to the corpus cavernosum of the penis. The term corpora cavernosa literally means "cave-like bodies".

The development of the reproductive system is the part of embryonic growth that results in the sex organs and contributes to sexual differentiation. Due to its large overlap with development of the urinary system, the two systems are typically described together as the genitourinary system.

<span class="mw-page-title-main">Clitoral hood reduction</span> Cosmetic surgical procedure

Clitoral hood reduction, also termed clitoral hoodectomy, clitoral unhooding, clitoridotomy, or (partial) hoodectomy, is a plastic surgery procedure for reducing the size and the area of the clitoral hood in order to further expose the glans of the clitoris.

<span class="mw-page-title-main">Vulva</span> External genitalia of the female mammal

In mammals, the vulva comprises mostly external, visible structures of the female genitalia leading into the interior of the female reproductive tract, starting at the vaginal opening. For humans, it includes the mons pubis, labia majora, labia minora, clitoris, vestibule, urinary meatus, vaginal introitus, hymen, and openings of the vestibular glands. The folds of the outer and inner labia provide a double layer of protection for the vagina. Pelvic floor muscles support the structures of the vulva. Other muscles of the urogenital triangle also give support.

<span class="mw-page-title-main">Yoni massage</span> A type of tantric erotic massage, focusing on the female erogenous zones

Yoni massage or yonic massage, derived from the word Yoni, a representation of the vulva which symbolizes the goddess Shakti, is a type of Tantric full-body massage. It primarily focuses on the labia, clitoris, G-spot, uterus, the breasts, the anus and other erogenous zones. Yoni massage is the female equivalent of a Lingam massage. The massage is viewed as therapeutic and is sometimes used as a method of relieving tension, pain, or general discomfort of the vagina. It has been claimed by some practitioners to be helpful to achieve fertilisation, although there is no scientific support for this claim.

References

  1. ↑ Blüm, Volker (2012). Vertebrate Reproduction: A Textbook. Springer Berlin Heidelberg. p. 74. ISBN   978-3-64271-074-2 . Retrieved November 19, 2023.
  2. ↑ McEntee, Mark (2012). Reproductive Pathology of Domestic Mammals. Elsevier Science. p. 192. ISBN   978-0-32313-804-8 . Retrieved November 19, 2023.
  3. ↑ Andrews, Anthony; Boden, Edward (2015). Black's Veterinary Dictionary. Bloomsbury Publishing. p. 484. ISBN   978-1-40814-955-3 . Retrieved December 15, 2023.
  4. ↑ Kumar, M.S.A. (2015). Clinically Oriented Anatomy of the Dog & Cat. Linus Learning. p. 1254. ISBN   978-1-60797-552-6.
  5. 1 2 3 4 Moore, Keith L.; Agur, Anne M. R.; Dalley II, Arthur F. (2010). Essential Clinical Anatomy, Fourth Edition. Lippincott Williams & Wilkins. p. 268. ISBN   9781609131128.
  6. 1 2 3 4 5 Farage, Miranda A.; Maibach, Howard I. (2006). The Vulva - Anatomy, Physiology, and Pathology. CRC Press. pp. 1–4, 14, 28–38. ISBN   978-0-8493-3608-9.
  7. 1 2 3 4 5 6 7 Crooks, Robert; Baur, Karla (2014). Our Sexuality. Cengage Learning. pp. 50–54, 113–116, 163–171. ISBN   978-1-133-94336-5.
  8. 1 2 3 4 Jones, Richard E.; Lopez, Kristin H. (2006). Human reproductive biology. Elsevier Science. pp. 55, 133–138, 154, 198–201. ISBN   9780080508368.
  9. ↑ Lloyd, Jillian; et al. (May 2005). "Female genital appearance: 'normality' unfolds" (PDF). British Journal of Obstetrics and Gynaecology. 112 (5): 643–646. CiteSeerX   10.1.1.585.1427 . doi:10.1111/j.1471-0528.2004.00517.x. PMID   15842291. S2CID   17818072.
  10. ↑ Hodges, Frederick Mansfield S.; Denniston, George C.; Milos, Marilyn Fayre (2007). Male and Female Circumcision: Medical, Legal, and Ethical Considerations in Pediatric Practice. Springer US. p. 10. ISBN   978-0-58539-937-9 . Retrieved November 24, 2023.
  11. ↑ Martin, Richard J.; Fanaroff, Avory A.; Walsh, Michele C. (2014). Fanaroff and Martin's Neonatal-Perinatal Medicine E-Book: Diseases of the Fetus and Infant. Elsevier Health Sciences. p. 1522. ISBN   978-0-32329-537-6 . Retrieved November 24, 2023.
  12. 1 2 3 4 5 6 7 8 Carroll, Janell L. (2011). Sexuality Now: Embracing Diversity. Cengage Learning. pp. 86–88, 116–120, 253–256. ISBN   978-0-495-60274-3.
  13. ↑ Ginger, Van Anh T.; Yang, Claire C. (2011). "Functional Anatomy of the Female Sex Organs" in Cancer and Sexual Health (PDF). Humana Press. pp. 13–23.
  14. ↑ Lamanna, Mary Ann; Riedmann, Agnes (2011). Marriages, Families, and Relationships: Making Choices in a Diverse Society. Cengage Learning. pp. A7. ISBN   9781133172826.
  15. ↑ "2022 Minnesota Statutes: 617.23 Indecent Exposure; Penalties". Minnesota Legislature: Office of the Revisor of Statutes.
  16. ↑ "2005 Idaho Code - 18-4116 — Indecent Exposure". Justia US Law.
  17. 1 2 3 Herbenick, Debby; Schick, Vanessa (2011). Read My Lips: A Complete Guide to the Vagina & Vulva. Rowman & Littlefield Publishers. Inc. pp. 148–158, 165, 233–240. ISBN   978-1-4422-0802-5.
  18. ↑ "Classification of female genital mutilation", Geneva: World Health Organization, 2014.
  19. ↑ Gruenbaum, Emma (2001). The Female Circumcision Controversy: An Anthropological Perspective, Philadelphia: University of Pennsylvania Press, pp. 2–3.
  20. ↑ Bonino, Emma (19 December 2012). "Banning Female Genital Mutilation", The New York Times.
  21. ↑ The Centrefold Project
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