What Is Vagina

The vagina (from Latin, literally "sheath" or "scabbard") is a fibromuscular tubular tract leading from the uterus to the exterior of the body in female placental mammals and marsupials, or to the cloaca in female birds, monotremes, and some reptiles. Female insects and other invertebrates also have a vagina, which is the terminal part of the oviduct. The Latinate plural (rarely used in English) is vaginae.

In common speech, the term "vagina" is often used to refer to the vulva or female genitals generally; strictly speaking, the vagina is a specific internal structure and the vulva is the exterior genitalia only.

Human anatomy

The human vagina is an elastic muscular canal that extends from the cervix to the vulva.^[1] Although there is wide anatomical variation, the length of the unaroused vagina is approximately 6 to 7.5 cm (2.5 to 3 in) across the anterior wall (front), and 9 cm (3.5 in) long across the posterior wall (rear).^[2] During sexual arousal the vagina expands in both length and width.^[3] Its elasticity allows it to stretch during sexual intercourse and during birth to offspring.^[4] The vagina connects the superficial vulva to the cervix of the deep uterus.

If the woman stands upright, the vaginal tube points in an upward-backward direction and forms an angle of slightly more than 45 degrees with the uterus. The vaginal opening is at the caudal end of the vulva, behind the opening of the urethra. The upper one-fourth of the vagina is separated from the rectum by the rectouterine pouch. Above the vagina is Mons Veneris. The vagina, along with the inside of the vulva, is reddish pink in color, as with most healthy internal mucous membranes in mammals. A series of ridges produced by folding of the wall of the outer third of the female vagina is called vaginal rugae. They are transverse epithelial ridges and their function is to provide the vagina with increased surface area for extension and stretching. Vaginal lubrication is provided by the Bartholin's glands near the vaginal opening and the cervix. The membrane of the vaginal wall also produces moisture, although it does not contain any glands. Before and during ovulation, the cervix's mucus glands secretes different variations of mucus, which provides a favorable alkaline environment in the vaginal canal to maximize the chance of survival for sperm.

The hymen is a thin membrane of connective tissue which is situated at the opening of the vagina. As with many female animals, the hymen covers the opening of the vagina from birth until it is ruptured during sexual or non-sexual activity. The tissue may be ruptured by vaginal penetration, a pelvic examination, injury, or certain types of activities, such as horseback riding or gymnastics. The absence of a hymen does not necessarily indicate prior sexual activity, as it is not always ruptured during sexual intercourse.^[5] Similarly, the presence does not necessarily indicate a lack of prior sexual activity, as it is possible for light activity to not rupture it, or for it to be surgically restored.

Physiological functions of the vagina

The vagina has several biological functions.

Uterine secretions

The vagina provides a path for menstrual blood and tissue to leave the body. In industrial societies, tampons, menstrual cups and sanitary napkins may be used to absorb or capture these fluids.

Sexual activity

The concentration of the nerve endings that lie close to the entrance of a woman's vagina can provide pleasurable sensation during sexual activity, when stimulated in a way that the particular woman enjoys. During sexual arousal, and particularly the stimulation of the clitoris, the walls of the vagina self-lubricate. This reduces friction that can be caused as a result of various sexual activities. Research has found that portions of the clitoris extend into the vulva and vagina.^[6]

With arousal, the vagina lengthens rapidly to an average of about 4 in.(8.5 cm), but can continue to lengthen in response to pressure.^[7] As the woman becomes fully aroused, the vagina tents (last ²⁄₃ expands in length and width) while the cervix retracts.^[8] The walls of the vagina are composed of soft elastic folds of mucous membrane skin which stretch or contract (with support from pelvic muscles) to the size of the inserted penis.

G-spot

For more details on this topic, see G-spot.

An erogenous zone referred to commonly as the G-spot is located at the anterior wall of the vagina, about five centimeters in from the entrance. Some women experience intense pleasure if the G-spot is stimulated appropriately during sexual activity. A G-Spot orgasm may be responsible for female ejaculation, leading some doctors and researchers to believe that G-spot pleasure comes from the Skene's glands, a female homologue of the prostate, rather than any particular spot on the vaginal wall.^[9][10][11] Some researchers deny the existence of the G-spot.^[12]

Childbirth

During childbirth, the vagina provides the channel to deliver the baby from the uterus to its independent life outside the body of the mother. During birth, the vagina is often referred to as the birth canal. The vagina is remarkably elastic and stretches to many times its normal diameter during vaginal birth.

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Cancer Of The Cervix. Prevention Is Better Than Cure

Many of my patients are scared of having abnormal Pap Smear. The idea strikes terror in their hearts as they think they may have cancer of the cervix. I recently had to do a hysterectomy on a 34 year old patient because her mother died from cervical cancer and her cervical cells on biopsy showed severe dysplasia. Even after removal of the diseased area on the cervix she still was scared and wanted hysterectomy because she saw how her mother suffered. I am therefore thrilled that finally there is a vaccine that will prevent this horrible disease.

My second patient had no insurance and hence had been using the emergency room(ER) for her healthcare. She went to the ER whenever she had any medical problems. I was called to the hospital to see her after she had been admitted with vaginal bleeding and abdominal pains. Pelvic examination showed a hard tumor in the vagina involving the right side of the pelvis. Further tests showed her right ureter, the tube that drains her right kidney to the bladder was blocked and the disease had spread beyond the pelvis. She died 2 months later.

Cancer of the cervix and genital warts are caused by the Human Papilloma Virus (HPV). The HPV affects the anus , vulva, vagina and penis and are transmitted by sex. There are many different types of HPV. If left untreated the disease can cause precancerous changes on the cervix that, if also untreated, can lead to cancer of the cervix. Other risk factors for cervical cancer include:

• Having sex at an early age
• Multiple sexual partners
• Sexual partners who have multiple partners or who participate in high-risk sexual activities
• Women whose mothers took the drug DES (diethylstilbestrol) during pregnancy in the early 1970s to prevent miscarriage
• Long-term use of birth control pills (more than 5 years)
• Weakened immune system
• Infections with genital herpes or chronic chlamydia infections
• Poor economic status (may not be able to afford regular Pap smears)

Fortunately, in June 2006, the Advisory Committee on Immunization Practices voted to recommend Gardasil to be used to prevent cervical cancer. Gardasil protects against four HPV types (16,18,6 and 11), which together cause 70% of cervical cancer and 90% of genital warts.

The vaccine, preferably, should be given to girls before they become sexually active. However it is recommended for the age group 9-26 years. It is assumed that even if sexually active women are infected they may not be infected with all the 4 types of HPV. Research on the safety and effectiveness of the vaccine in women over 26 years has not been completed, though some physicians have suggested that the vaccine be given to women over 26 years old. Three injections are given over 6 months. The second and third doses should be given at two and six months after the first dose.

The vaccine would be a boon to the third world where no or minimal screening for cervical cancer is done. Many patients go to the hospital when they start bleeding at which time the cancer is at an advanced stage. It is in this light that the Brazil government should be commended for considering giving the vaccine free of charge to its qualified citizens. Even in the US, the cost may prevent some people from getting the vaccine. That is why we should applaud the announcement by the government of New Hampshire that it is going to offer the vaccine free to its qualified citizens - ( about 17,000 girls and women).

The 2 patients above show how important this discovery is. People are still dying in this country from this disease which is preventable. It is my hope that the insurance companies will pay for the vaccination to wipe out this scourge form this country.