Hymen

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"Himen" redirects here. For the village in Iran, see Himen, Iran.

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This article is about the vaginal membrane. For the god and other uses, see Hymen (disambiguation).
Hymen
Gray1229.png
External genital organs of female. The labia minora have been drawn apart.
Details
Latin hymen vaginae
Identifiers
MeSH A05.360.319.779.479
TA Lua error in Module:Wikidata at line 744: attempt to index field 'wikibase' (a nil value).
TH {{#property:P1694}}
TE {{#property:P1693}}
FMA {{#property:P1402}}
Anatomical terminology
[[[d:Lua error in Module:Wikidata at line 863: attempt to index field 'wikibase' (a nil value).|edit on Wikidata]]]

The hymen is a membrane that surrounds or partially covers the external vaginal opening. It forms part of the vulva, or external genitalia, and is similar in structure to the vagina.[1][2] In children, although a common appearance of the hymen is crescent-shaped, many shapes are possible.[1]

The effects of sexual intercourse and childbirth on the hymen are variable. If the hymen is sufficiently elastic, it may return to nearly its original condition. In other cases, there may be remnants (carunculae myrtiformes), or it may appear completely absent after repeated penetration.[3] Additionally, the hymen may be lacerated by disease, injury, medical examination, masturbation or physical exercise. For these reasons, the state of the hymen is not a conclusive indicator of virginity.[2][3]

Development and histology

The genital tract develops during embryogenesis, from the third week of gestation to the second trimester, and the hymen is formed following the vagina. At week seven, the urorectal septum forms and separates the rectum from the urogenital sinus. At week nine, the Müllerian ducts move downwards to reach the urogenital sinus, forming the uterovaginal canal and inserting into the urogenital sinus. At week twelve, the Müllerian ducts fuse to create a primitive uterovaginal canal called unaleria. At month five, the vaginal canalization is complete and the fetal hymen is formed from the proliferation of the sinovaginal bulbs (where Müllerian ducts meet the urogenital sinus), and becomes perforate before or shortly after birth.

The hymen has no nerve innervation. In newborn babies, still under the influence of the mother's hormones, the hymen is thick, pale pink, and redundant (folds in on itself and may protrude). For the first two to four years of life, the infant produces hormones that continue this effect.[4] Their hymenal opening tends to be annular (circumferential).[5]

Past neonatal stage, the diameter of the hymenal opening (measured within the hymenal ring) widens by approximately 1 mm for each year of age.[6] During puberty, the hymenal opening can also be enlarged by tampon or menstrual cup use, pelvic examinations with a speculum, regular physical activity or sexual intercourse.[1] Once a girl reaches puberty, the hymen tends to become very elastic. In one survey, only 43% of women reported bleeding the first time they had intercourse, indicating that the hymens of a majority of women are sufficiently open to prevent tearing.[1][4]

Prepubescent girls' hymenal openings come in many shapes, depending on hormonal and activity level, the most common being crescentic (posterior rim): no tissue at the 12 o'clock position; crescent-shaped band of tissue from 1–2 to 10–11 o'clock, at its widest around 6 o'clock. From puberty onwards, depending on estrogen and activity levels, the hymenal tissue may be thicker, and the opening is often fimbriated or erratically shaped.[5] In younger children, a torn hymen will typically heal very quickly. In adolescents, the hymenal opening can naturally extend and variation in shape and appearance increases.[1]

A glass or plastic rod of 6 mm diameter having a globe on one end with varying diameter from 10 to 25 mm, called Glaister Keen rod, is used for close examination of the hymen or the degree of its rupture. In forensic medicine, it is recommended by health authorities that a physician who must swab near this area of a prepubescent girl avoid the hymen and swab the outer vulval vestibule instead.[4] In cases of suspected rape or child sexual abuse, a detailed examination of the hymen may be performed, but the condition of the hymen alone is often inconclusive.[2]

After giving birth, the vaginal opening usually has nothing left but hymenal tags (carunculae myrtiformes) and is called parous introitus.

Anatomic variations

Various types of hymen (the dark areas represent the vaginal opening)

Variations of the female reproductive tract can result from agenesis or hypoplasia, canalization defects, lateral fusion and failure of resorption, resulting in various complications.[6]

  • Imperforate:[7][8] hymenal opening nonexistent; will require minor surgery if it has not corrected itself by puberty to allow menstrual fluids to escape.
  • Cribriform, or microperforate: sometimes confused for imperforate, the hymenal opening appears to be nonexistent, but has, under close examination, small perforations.
  • Septate: the hymenal opening has one or more bands of tissue extending across the opening.

Hymenorrhaphy

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Main article: Hymenorrhaphy

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See also: Virginity fraud

In some cultures, an intact hymen is highly valued at marriage in the belief that this is a proof of virginity.[9][10][11] Some women undergo hymenorrhaphy, a restoration of their hymen for this reason.[11][12]

Womb fury

In the sixteenth and seventeenth centuries, medical researchers used the presence of the hymen, or lack thereof, as founding evidence of physical diseases such as "womb-fury", i.e. (female) hysteria. If not cured, womb-fury would, according to these early doctors, result in death.[13][14]

Other animals

Due to similar reproductive system development, many mammals, including chimpanzees, elephants, manatees, whales, and horses retain hymens.[15][16]

See also

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 Emans, S. Jean. "Physical Examination of the Child and Adolescent" (2000) in Evaluation of the Sexually Abused Child: A Medical Textbook and Photographic Atlas, Second edition, Oxford University Press. 61-65
  2. ↑ 2.0 2.1 2.2 Lua error in package.lua at line 80: module 'strict' not found.
  3. ↑ 3.0 3.1 Lua error in package.lua at line 80: module 'strict' not found.
  4. ↑ 4.0 4.1 4.2 McCann, J; Rosas, A. and Boos, S. (2003) "Child and adolescent sexual assaults (childhood sexual abuse)" in Payne-James, Jason; Busuttil, Anthony and Smock, William (eds). Forensic Medicine: Clinical and Pathological Aspects, Greenwich Medical Media: London, a)p.453, b)p.455 c)p.460.
  5. ↑ 5.0 5.1 Lua error in package.lua at line 80: module 'strict' not found.
  6. ↑ 6.0 6.1 Lua error in package.lua at line 80: module 'strict' not found.
  7. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  8. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  9. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  10. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  11. ↑ 11.0 11.1 Lua error in package.lua at line 80: module 'strict' not found.
  12. ↑ Hymenoplasty is depicted in a fictional context in "Everett Poe", an episode of the television series Nip/Tuck that was broadcast in 2007.
  13. ↑ Berrios GE, Rivière L. (2006) 'Madness from the womb'. History of Psychiatry. 17:223-35.
  14. ↑ The linkage between the hymen and social elements of control has been taken up in Marie Loughlin's book Hymeneutics: Interpreting Virginity on the Early Modern Stage published in 1997
  15. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  16. ↑ Lua error in package.lua at line 80: module 'strict' not found.

External links

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