Vagina is the fibro-muscular tube in females, which extend from the vulva externally to the uterus internally. It is about 3 inches long and has anterior and posterior walls, which are normally in contact with each other. The vagina, along with the inside of the vulva is reddish-pink in color.
In an upright standing woman, the vaginal tube points in an upward-backward direction (from external to internal side) and forms an angle of about 45 degrees with the uterus. Opening of the vagina is at the caudal end of the vulva, behind the opening of the urethra.
At the upper end of the vagina, the anterior wall is pierced by the cervix which projects into it. The area of vaginal lumen, which surrounds the cervix, is divided into four fornices: anterior, posterior, right lateral and left lateral. These fornices are the deepest portions of the vagina, extending into the recesses created by the vaginal portion of the cervix.
Hymen is a thin mucosal fold that is situated at the opening of the vagina. It is present in the vaginal orifice of a virgin and is perforated at its center. After childbirth, the hymen consists only of tags.
- Rectouterine pouch (upper third of vagina)
- Ampulla of rectum (middle third of vagina)
- Perineal body (lower third of vagina)
- Ureter (upper part of vagina)
- Anterior fibers of levator ani (middle part of vagina)
- Urogenital diaphragm (lower part of vagina)
- The arterial supply is provided by the vaginal artery, which is a branch of the internal iliac artery. Vaginal branch of uterine artery also supplies the vagina.
- Venous drainage is by way of vaginal veins that form a plexus around the vagina and drain into the internal iliac vein.
Lymph from the upper third of vagina is drained into the external and internal iliac nodes. From the middle third is drained into the internal iliac nodes only and from the lower third is drained into the superficial inguinal nodes.
Fibers from inferior hypogastric plexus innervate the vagina.
Vagina is supported by a number of structures so the region, as described below:
- Upper part of vagina: It is supported levatores ani muscles, and transvers cervical, pubocervical and sacrocervical ligaments.
- Middle part of vagina: It is supported by the urogenital diaphragm.
- Lower part of vagina: It is supported by the perineal body.
Vagina is the female genital canal that provides pleasurable sensations during sexual intercourse. The walls of the vagina self-lubricate to reduce the friction that can be caused by sexual activity.
In addition, vagina also forms part of the birth canal and it’s the excretory duct for the menstrual flow.