Annisettanta | Triennale di Milano

The Hymen is a fold of mucous membrane which surrounds or partially covers the external vaginal opening. It forms part of the vulva, or external genitalia. The most common formation of the hymen is crescentic or crescent-shaped, although several other formations are possible. After a woman gives birth she may be left with remnants of the hymen called carunculae myrtiformes or the hymen may be completely absent.
The hymen has no known anatomical function. In societies which value chastity, the greatest significance of the hymen is a traditional belief that an intact hymen indicates a state of intact virginity. However, it is not possible to confirm that a woman or post-pubescent girl is a virgin by examining the hymen. A physician routinely checks the appearance of the hymen of baby girls at birth [citation needed], and again during all future pelvic examinations. In cases of suspected rape or sexual abuse a detailed examination of the hymen may be carried out, however the condition of the hymen alone is often inconclusive or open to misinterpretation, especially if the patient has reached puberty. [from wiki]