Anatomy and physiology of the vagina
The vagina is a passageway that connects the cervix (opening of the uterus) to the outside of the body. It is also known as the birth canal.
The vagina is a thin-walled, muscular tube about 7.5–10 cm long. It is located in the pelvis (lower part of the abdomen) between the bladder and rectum. The vagina extends from the cervix to the vulva (the external genitals).
The wall of the vagina is composed of 3 layers:
- mucosa – epithelial tissue
- inner layer of squamous epithelial cells
- also called the epithelium or epithelial lining
- muscularis – muscle tissue
- adventitia – connective tissue
The vaginal walls are usually collapsed so that they touch each other. The walls have many folds, which let the vagina enlarge during sexual intercourse and childbirth.
Glands near the opening of the vagina secrete mucus to keep the mucosa moist.
The vagina has 3 main functions:
- provides a passageway for menstruation (discharge of blood and mucosal tissue from the uterus)
- receives the penis during sexual intercourse and holds the sperm until they pass into the uterus
- provides a passageway for childbirth