Hymen

Generality

The hymen is a more or less flexible mucous membrane that partially covers the external orifice of the vagina. This septum is usually torn by penetration of the penis during the first sexual intercourse; for this reason, many cultures have made it the symbol of purity.

However, its integrity is not a reliable indicator of female virginity, as the hymen membrane can easily rupture for many other reasons, such as, for example, a fall from a bicycle or the use of tampons.

The hymen is one of the organs showing the greatest morphological variations. For example, the central opening (called the hymen orifice) can be rounded or half-moon, or the membrane can have more than one hole.
From a clinical point of view, the most important aspect is that of the imperforate hymen, in which the membrane completely covers the orifice through which the vaginal canal opens to the outside.

So is the hymen

The hymen is a thin and elastic membrane, essentially formed by a folding of the mucosa, which surrounds and partially (in rare cases, completely) closes the vulvo-vaginal orifice.

Curiosity. The "origin of the anatomical term" hymen "derives from the Greek" hymèn ", which means membrane. However, in Greek mythology, Hymen (or Hymenaios) was also the name of the deity responsible for the protection of the spouses and the rite of marriage.

Where is it

The hymen is located in correspondence with the passage between the posterior vaginal wall and the vestibule.
Anatomically, this structure is part of the external genitalia, which also include the following structures:

• Upstream: relief of skin and underlying adipose tissue centrally located in the pelvic region.
• Large and small labia: group of external and internal folds that surround the external orifice of the vagina.
• Vestibule: area enclosed by the labia minora leading to the meatus (orifice) of the vagina and urethra.
• Clitoris: small erectile organ located in front of the vestibule.
• Vestibular glands: pair of small glands that secrete a lubricating fluid that facilitates the penetration of the penis into the vagina during sexual intercourse.

The hymen can be observed by the woman herself, with a small mirror, between the lips of the vulva, stretched to the limit of the canal and the vaginal vestibule.

Anatomical features

In the hymen it is possible to distinguish two faces: a vestibular (facing outwards) and a vaginal one (facing inwards and consisting of an epithelium similar to that of the vagina).

Between these two sheets of mucosa, a layer of connective tissue is interposed, rich in elastic fibers, smooth muscle fiber cells, vessels and nerve endings.
The hymen also has two margins:

• Free: circumscribes the orifice of the hymen; it is subtle and seldom regular.
• Adherent: separated from labial formations by a nympho-hymenal groove, it is always well pronounced.

An intact hymen typically has one or more openings that allow menstrual blood and vaginal secretions to escape.

Figure: Different Types of Hymen; the gray areas represent the vaginal opening. From en.wikipedia.org

The effects of intercourse and childbirth on the hymen are variable.
After the first sexual intercourse, these orifices are destined to tear, giving rise to a certain number of flaps (hymenal lobules), variable in volume and shape, arranged around the vaginal orifice. However, it can also happen that the membrane is so elastic not to be affected by penetration.
After the first birth, with the passage of the fetal head, there is a further opening and most of the lobules undergo necrosis. The parts of the hymen that remain, however, produce some scarred formations around the vaginal orifice, more or less pedunculated, called hymenal caruncles.
In general, therefore, the appearance of the hymen varies depending on whether an intact hymen or its residues are present:

• In most adult women, the hymen is not intact and the external orifice of the vagina appears oval; on the contour of the latter, the vaginal mucosa continues directly with that of the vestibule.
• In virgin girls, on the other hand, the hymen membrane is intact and delimits the opening of the vaginal canal.

What is it for

The function of the hymen is not yet fully understood. This structure separates the entrance to the vaginal cavity from the vulva, allowing menstrual blood to pass through one or more small openings.
According to some scientific interpretations, this membrane has the function of a barrier, protecting the vaginal opening and the areas immediately surrounding the intake during the development of the female genital system until puberty is reached.
According to other scholars, however, the hymen would be the result of evolution: its presence would serve to push the woman to seek strong ties with her partner and to avoid the randomness of sexual relations.

Curiosity. The hymen is also present in various animals. In particular, many primates (such as chimpanzees), marine mammals (eg manatees and whales), but also elephants, guinea pigs and horses have it.

Anatomical variations

The hymen has very different characteristics from woman to woman: at least 8 different conformations have been found. A common aspect of the membrane is crescent-shaped, however the shape and resistance of the hymen vary widely.