Family Doctor Books

Published in association with the British Medical Association

Family Doctor Books

Preview of Understanding Thrush, Cystitis & Women's Genital Symptoms

The female genital region: normal structure and function

The genital region

The vulva

The vulva is the external, visible, outer and inner lips of skin, which partially conceal (from front to back) the clitoris, the opening of the urethra (from where urine emerges) and the vaginal opening, called the introitus. Further back still, beyond the vulva, is the anus.

The vulva contains tiny glands that help to keep the skin in this area moist and to provide lubrication in preparation for sexual intercourse. These glands produce a protective, waterproof film over the skin surface. If allowed to build up, it can seem as if the vulva has a thick creamy substance over it which could be confused with a vaginal discharge. At other times this waterproofing forms a thin film which can almost be peeled off, especially if the area has been washed with drying agents (astringents) such as some body washes.

Your vulva is a very sensitive piece of skin, with almost as many nerve endings as your lips or mouth, so you will tend to notice immediately when something is wrong.

Most commonly you may notice itching, soreness or pain but, as it is easy to touch the area, you may also detect changes in texture or the development of lumps. Viewing your vulva, however, is not so easy. You can examine your vulva by crouching over a carefully placed, brightly lit mirror, but this is difficult to arrange even when you are feeling well. As a result, subtle changes are often missed. Also, because most women seldom examine themselves in this region, they may be unfamiliar with the normal appearance of their vulva and are often unable to decide whether or not its appearance has changed.

The normal vulva varies hugely in appearance from woman to woman. The inner and outer lips (labia minora and labia majora) can be anything from hardly present at all to quite large flaps of skin. The introitus is nearly always surrounded by irregular outgrowths – rather like sea anemone tentacles – which are the remnants of the hymen (the membrane covering the vaginal opening in early life). Even in virgins the hymen is often irregular, and it is a myth that anyone can reliably tell by examining a woman whether or not she is still a virgin.

The vulva is the external visible outer and inner lips of skin, which partially conceal the clitoris, the opening of the urethra and the vaginal opening. Your vulva is a very sensitive piece of skin, with almost as many nerve endings as your lips or mouth, so you will tend to notice immediately when something is wrong.

The vagina

The vagina is an expansive tube that is usually flattened from back to front. It has the potential to lengthen and widen considerably, however – not only to make room for a penis, but also for a baby’s head and body. The necessary stretching is made possible because of the way the vaginal wall is corrugated, giving it an unusually large surface area.

The vagina contains a complex mix of micro-organisms, proteins, mucus and fluid which contribute to normal vaginal secretions (see below). This produces an acid, self-cleansing environment which normally maintains a healthy, delicate balance of all its constituents within strict limits.

The vagina opens to the outside world in the middle of the vulva, the introitus. As there are relatively few nerve endings in your vaginal walls, you will not usually feel pain or itching in the vagina itself.

The cervix, uterus, fallopian tubes and ovaries

In general, the deeper inside your body an organ is found, the less sensitive it is to pain and the more difficult it may be for you to pinpoint the exact site of any discomfort. This is true of almost all the organs in your body cavity. Pain originating deep in your pelvis usually feels vague and most people, including their doctors, find it hard to say for certain where it is coming from.

Your uterus, or womb, is an organ the size and shape of an upside-down pear. It is really a muscle with a central cavity, rather like a very thick-walled bag. It lies deep in your pelvis and connects with the outside via the junction between the cervix (which is Latin for neck) and the vagina. Two fallopian tubes emerge to the right and left side of your uterus; the other end of each fallopian tube is loosely in contact with an ovary.

Cross-section through the female reproductive organs. Your uterus or womb is the size and shape of an upside-down pear. It is a muscle with a central cavity connected to the outside by the vagina and via the two fallopian tubes to the two ovaries.

Your cervix (neck of the womb) is a muscular ring around the opening of your uterus. It can be likened to a thick rubber band ready to hold the uterus closed around a fetus in pregnancy. The cervix and uterus have very few nerve endings and are not sensitive to ordinary touch. The cervix is not even tender when it is inflamed.

The cervix protrudes into the upper part of the vagina, and the moist membrane lining the uterus and the skin lining the vagina meet on its surface. The uterine skin cells look tall and thin under a microscope (known as columnar epithelium), whereas the vaginal cells look plate like or flattened (squamous epithelium). The actual point where the two types of epithelium meet is called the squamocolumnar junction and, under the influence of oestrogen hormones throughout your reproductive life, this changes position by moving up closer to the cervical canal, or down over the outer cervix.

When the columnar epithelium, which normally lines the uterus, spreads out onto the surface of the cervix, it is known as ectopy or, by its older term, erosion. An ectopy is a fragile area of skin containing lots of secretory glands. The normal fluid and bacteria in the vagina irritate these moist lining cells and cause them to produce increased secretions. It is, however, common to have ectopy and rare for it to be extensive enough to cause troublesome discharge. The exception to this is in pregnancy when oestrogen levels are high and a large ectopy contributes to the increase in secretions at this time.

As the junction between the columnar and squamous cells moves in and out, cells in the area where the cervix and uterus meet change type frequently in response to changing hormone levels. A particular area may contain squamous cells on one occasion, but columnar cells on another. As cancer often develops in places where the cell type fluctuates, this is thought to be why cervical cancer is most likely to develop at the squamocolumnar junction.

The urinary tract

Your bladder is located deep in your pelvis, in front of your uterus. Its purpose is to store urine until it is ready for voiding. Urine is expelled from your body by contraction of your bladder’s muscular wall. Urine produced by your kidneys flows into your bladder down two muscle-walled tubes known as ureters. Your bladder connects with the outside through another single tube known, rather confusingly (because of the similarity of the words), as the urethra. The urethra is relatively short in women, but in men it traverses the length of the penis and is therefore much longer.

The urethra follows the rule that, the closer a structure is to your body surface, the more sensitive it is. The burning pain you feel when urine passes through an inflamed urethra during a urinary tract infection (UTI), commonly called cystitis, is known as dysuria. Inflammation of your bladder, on the other hand, leads to less specific symptoms and you may notice only a dull pelvic or back ache. The main symptom of a UTI – frequent, painful urination – results from inflammation of your bladder, which then contracts too easily when only a small amount of urine is present.

As urine flows out of your urethra it runs over your vulva. Pain on passing urine is usually attributed to a UTI but, if your vulva itself is sore, urine that is not infected may irritate the tender skin and cause pain as a result of the abrasive chemicals that it contains.

Normal variations in vaginal secretions

The volume and consistency of vaginal secretions are usually under hormone control. These secretions are most noticeable between puberty and the menopause and are at a maximum during pregnancy. There is also a smaller increase in the amount of secretions produced each month at the time of ovulation. Sexual excitement will also increase the amount of fluid produced as the vagina lubricates itself ready for intercourse.

Most of the secretions come from the vaginal walls. As a result of its large surface area, the vagina is capable of producing a large volume of fluid. Some of the normal fluid also comes from the glands around the vulva. The largest of these glands is Bartholin’s gland, with one being situated in the rear part of each labium minorum. These glands are important because they can become infected and develop into an abscess. A small amount of secretion comes from the cervix and uterus. In pregnancy, the vagina and cervix produce increasing amounts of fluid.

The range in the amount of normal secretion produced throughout life is vast, but if you are of childbearing age you will probably experience daily staining of your underwear. It is unusual, however, for there to be sufficient to require the regular use of panty liners.

Before puberty

In prepubescent girls, the vagina seems able to resist most of the infections that affect adult women. There are organisms in the vagina but they tend to be different from those in adults and they do not cause problems. It is rare for a girl to develop genital problems, unless they are caused by skin disease or if the girl’s vagina has been subjected to some sort of physical interference or damage.

After puberty

After puberty, a number of healthy bacteria are found in the vagina of which the most important are known as lactobacilli. These help to maintain an acid environment, compete for available nutrients, and also secrete certain chemicals which help to prevent unwanted bacteria and yeasts from becoming established.

Pregnancy

In pregnancy, the cervix, vagina and vulva become larger, with more blood flowing to them and more secretions coming from them. This increase usually starts to become apparent in the first few weeks of pregnancy and may even be the first sign of pregnancy that you notice. Pregnant women are also more prone to vaginal infections and cystitis because of changes in immunity, and because of the effects of pregnancy hormones.

After the menopause

When oestrogen hormone levels decline at the menopause, the vaginal skin thins, the glands gradually stop working and their secretions decline. As a result, the type of bacteria normally found, including the beneficial lactobacilli, also begin to change. This leads to dryness which may be uncomfortable – especially during intercourse – and may make vaginal infections and cystitis more likely.

KEY POINTS

It is important to be aware of the normal appearance of your genital region so that you can tell more easily whether something is wrong
Vaginal secretions are normal and vary in appearance and
quantity, depending on your age, menstrual cycle and hormone levels
Your vagina, cervix and uterus do not contain many nerve
endings so pain or discomfort originating from within these organs is vague and hard to pinpoint
Most urinary tract problems cause painful and/or frequent
passing of urine

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