The vagina is positioned in your pelvic cavity anterior to your rectum and posterior to your urinary bladder.
The vagina’s inner surface is creased that provides super flexibility and increased friction during copulation.
The vagina’s inner lining is prepared of non-keratinized (the surfaces that remain moist with secretions from the body) stratified squamous epithelial cells. These cells provide a safeguard from friction to the vagina’s primary layers.
The runny secretions generated by the vaginal epithelium grease the vagina and contain an acidic pH for preventing bacteria growth and the yeast. The acidic pH also creates a hostile atmosphere in the vagina for sperm.
Contrarily, the males produce an alkaline fluid known as semen for neutralizing the acid and improving the sperm survival. Beneath the epithelial layer, the lamina propria layer of connected tissue with several elastin fibers is located.
This layer helps in developing the vagina’s ability to stretch as per the requirement of the situation. Below the lamina propria layer, a smooth muscle cell layer is located that facilitates the vagina to get bigger and, at times, triggers contractions during copulation and the birth of a baby as per the need of the situation.
The outmost cover of the vagina surrounds the smooth muscle. This layer is called tunica externa. It is a layer of intense irregular connecting tissues forming an outer shielding shell of the vagina. In the copulating act, the vagina works as the receptacle of the penis and moves sperm to the Fallopian Tubes and the Uterus.
The flexible makeup of the vagina helps it in stretching in both diameter and length for accommodating the penis. At the time of delivering a baby, the vagina plays the role of a birth canal and performs the task of bringing the fetus out of the uterus and the mother’s body.
Yet again, the vagina’s flexibility helps it to significantly enlarge its diameter for accommodating the fetus. Conclusively, the vagina offers a gateway for the menstrual flow/periods coming from the uterus to make an exit out of the body in menstruation.