Hymen and Virginity
The hymen is a soft piece of tissue which is attached to the opening of the vagina. It is attached in a circular form around the opening of the vagina, and because of it the vaginal opening appears to be smaller than what it really is. To the best knowledge of most experts, the hymen serves no purpose. Ordinarily, when a girl has sexual intercourse for the first time, the hymen gets torn and damaged in several places, with the entry of the penis into the vagina. This leads to some bleeding and some pain. During subsequent intercourses, and during childbirth, parts of the hymen keep getting broken off, until the woman hardly has any hymen.

However, the absence or presence of hymen is not at all a reliable indicator of the virginity of a girl. A girl may not have a hymen and still be a virgin, it might have got broken during vigorous exercise or masturbation. On the other hand, a woman may have a hymen in spite of having had sexual intercourse many times, and or even after having given birth. In these cases, the structure and angle of attachment of the hymen is such that during intercourse, and during birth, it just glides back and lies on the walls of the vagina, and thus does not get broken.