The vagina (vagina) is the internal genital organ of a woman, which is presented in the form of an elastic muscle tube, localized between the vulva and cervix. The internal structure of the vagina is represented by the mucous membrane, which is lined with stratified squamous epithelium. The middle layer of the organ consists of smooth muscles. In the upper part of the vagina, the muscles pass into the myometrium. The muscles of the lower part of the vagina are stronger and are woven into the muscles of the perineum. Outside, this genitals is covered with adventitia. The vagina has a folded structure, that is, its walls are in contact with one another. Given the structure of the vagina, this organ can easily change its size during intercourse and the birth of a baby. During childbirth, the vagina can expand to 100-120 mm in diameter, on average its length is from 80 to 120 mm, and its width is from 20 to 30 mm.
The lower part of the vagina opens in the vestibule, which is closed by the virgin hymen in hymen. Until now, the physiological significance of this hymen is not known. In almost all nations, it is considered evidence of virginity. It should be said that it comes in various shapes and sizes, so reliable evidence of virginity is not. The hymen is very thin, so it is easy to damage it during strenuous physical exercises (horse riding, running), masturbation or the introduction of tampons.
In the process of growth and development, the structure of the female vagina undergoes some changes. In young girls, it is significantly less compared to adult women. Female steroid hormones (estrogens), which are synthesized in the ovaries, affect the structure of the vagina. The wall thickness of this organ in women who are of childbearing age is much greater than in women during menopause. It should be noted that not only the structure of the vagina changes, but also its biochemical composition. So, for example, during the childbearing period of a woman’s life, vaginal discharge is slightly acidic. An acidic environment prevents the growth of pathogenic microorganisms. However, before puberty and during menopause, the environment in the vagina has a slightly alkaline reaction, and this, as you know, can provoke the multiplication of bacteria and cause atrophic vaginitis.
Vaginal secretion is synthesized in the cervical canal, as well as the Bartolium glands, white with a specific characteristic odor. During intercourse, secretion can leak through the vaginal epithelium into the vaginal canal. Vaginal discharge in small quantities is normal for all women. Hypersecretion occurs during sexual arousal and ovulation. Abundant discharge indicates the presence of inflammatory processes in this organ. The secretion process is regulated by hormones. During menopause, the level of estrogen in the blood decreases significantly, while there is dryness of the vaginal mucosa, as well as pain during intercourse.
In the upper part of the vagina is located the cervix, which has a kind of hole that is closed by a mucous cervical tube. The structure of the vagina has a characteristic feature in the innervation. This organ has a small number of nerve endings; therefore, it is not the main erogenous zone of a woman.
Recently, many experts claim that the so-called G-spot, which is responsible for the fullness of orgasm, is localized in the vagina. Scientific studies have proved that on the walls of the vagina (at a depth of 2-3 cm) there is a characteristic area with a diameter of about 1 cm. Stimulation of this area gives women a lot of pleasant sensations.