Where is the first female model?

The hymen is a ring-shaped semi-closed membrane fold at the vaginal opening, which contains connective tissue, blood vessels and nerve endings. There is a hole in the center of the hymen, and the shapes of the holes include half-moon shape, round hole shape, oval shape, sieve shape, etc. Its thickness is approximately 2 mm. The hymen is the channel through which menstrual blood is discharged during puberty. After sexual intercourse begins, the penis is inserted into the vagina. The development of hymen varies greatly, and its toughness varies from person to person. The hymen can be observed only when the vulva is exposed. The hymen seen on the human body is very different from the model shown in the picture, and its shapes come in various shapes.