A woman's reproductive system coordinates an incredible environment to produce and nurture a new person. A woman's body not only contributes half of the genetic material needed to create a baby but also provides the optimum conditions for her egg to become fertilised by the man's sperm, so that her newly conceived baby can implant in her womb.
Her body then changes to protect, nourish and accommodate the growth of her baby for about 9 months, before the baby is ready to leave her body to survive independently.
The following provides an overview of the non-pregnant female reproductive system. We will first describe the woman's external genitals before explaining the internal reproductive organs.
Woman's external genitals
A woman's external genitals are collectively known as her 'vulva', which means 'covering'. A woman's vulva is made up of several structures that surround the entrance to her vagina. Each structure has its own separate function and are as follows:
The 'labia majora' are the two large folds of fatty tissue on either side of the vagina. (The word 'labia' means 'lips' and 'majora' means 'main'.) The labia majora are covered on the outer surface with skin and pubic hair and contain sweat glands. The inner surfaces of the 'lips' are free from hair, and covered by a moist, slippery skin known as a 'mucous membrane'. The size of each woman's labia majora will vary considerably from woman to woman and their main function is to protect the other parts of her genitalia lying between them. The tissue that forms the labia majora in baby girls, is the same tissue that forms the scrotum in baby boys, when they are developing in the womb.
The 'labia minora' (or 'small lips') lie within the two labia majora. They are soft, delicate folds of skin that contain connective tissue but no fat. The labia minora are covered with moist, shiny mucous membranes and have no pubic hair. They surround the vaginal opening and meet at the top to cover the woman's "Small organ above the woman's vagina that is usually stimulated for sexual pleasure".
The main function of the labia minora is to lubricate the skin around the genitals and provide bactericidal secretions to help protect against infections. The size of each woman's labia minora will vary. Some women have labia minora that protrude past their labia majora, while others will lie totally inside the labia majora. Both are normal and do not affect the way they function.
The clitoris is a small organ that lies at the top of the vulva between the folds of the labia minora. The clitoris is the most erotically sensitive part of the female genital area and is covered by the top part of the labia minora 'lips'. Here the labia minora form a 'hood' (known as the 'prepuce'), to cover and protect the sensitive end of the clitoris. The clitoris has a very rich blood and nerve supply and when it is touched and stimulated, the woman becomes aroused, as it fills with blood and becomes firm and erect, producing sexual enjoyment.
The female clitoris is the equivalent to the male penis, being formed in the womb from the same tissue that forms the tip the penis (known as the 'glans'). The fold of labia minora that passes over the clitoris in baby girls is equivalent to the male foreskin that covers the tip of the penis in baby boys.
The vaginal vestibule (or 'entrance') is the area enclosed by the labia minora and is usually only visible when the labia (or lips) are parted. The vestibule contains the vaginal opening. At the base of the vaginal opening are two pea-sized glands known as 'Bartholin's glands'. These are positioned on either side of the vaginal opening, at 4 and 8 o'clock, (if comparing the vaginal opening to the face of a clock.) These glands secrete fluid for lubrication during sexual arousal, to allow the entrance of the vagina to be moist, so that the penis may enter more easily during intercourse. The woman's Bartholin's glands are equivalent to the Cowper's glands in men, which also produce a lubricating fluid during sexual arousal.
The entrance to the vagina is partially covered by a thin, stretchable membrane called the 'hymen'. Small openings in the hymen allow menstrual blood to be passed when a girl reaches puberty. Each woman's hymen will vary considerably in elasticity. The hymen may be stretched or slightly torn during the first penetrative sexual intercourse and more so after giving birth to a baby vaginally. However, the hymen can also be broken through strenuous exercise, masturbation or using tampons. Once the hymen is broken, the irregular tags of remnant tissue remain. These are medically known as 'hymenal tags' or 'carunculae myrtiformes'.
The urethra meatus is the external opening of the tube that carries urine from the bladder (the tube is known as the urethra). The urethral opening is located below the clitoris and just above the vaginal opening. However, it is often difficult to see from the outside because it is embedded in the soft tissues of the vaginal vestibule.
The perineal body is the area between the opening of the vagina and the anus (also referred to as the 'perineum'). The perineal body is made of strong, flexible muscles covered by skin. The muscles intermingle with elastic fibres and connective tissue in a unique way to achieve a remarkable amount of flexibility. This enables the perineum to stretch during childbirth, as a baby's head presses against it, and pushes past it, to be born.
Woman's internal reproductive organs
The woman's internal reproductive organs have a unique role in producing an egg to be fertilised, before facilitating conception and then growing and nourishing the developing baby. The main reproductive organs include the:
A woman's vagina is a muscular tube (or canal) that extends upwards and slightly backwards from the vaginal opening to reach the uterus (or womb). The vaginal canal sits between the bladder (at the front) and the rectum (at the back). The lining of the vagina (or vaginal walls), are covered with folds of mucous membrane skin (called rugae). These folds allow the vagina to stretch to accommodate the use of tampons during menstruation, the penis during sexual intercourse and to give birth to a baby as they descend down the vagina to be born.
The mucous lining of the vagina constantly sheds its top layer of skin cells. This is a natural 'self-cleansing' mechanism. The vagina contains healthy bacteria called ' Doderlein's bacillus'. The bacillus produce lactic acid to give the vagina an acidic pH of about 4.5. It is this acidic environment that discourages the survival of unwanted germs that may contaminate the vagina, such as fungal infections (or thrush).
The vagina is surrounded and supported by pelvic muscles. The pelvic muscles give the vagina natural tone (to hold a tampon in place or to increase sexual pleasure). The woman also has the ability to relax and contract these muscles voluntarily, to increase their tone (known as pelvic floor exercises).
Uterus and cervix
The uterus is also known as the 'womb'. The non-pregnant uterus is a hollow, pear-shaped organ, about the size of a clenched fist, with thick muscular walls. The uterus sits within the pelvic bones of the woman, behind her bladder and in front of the rectum (or bowel). The uterus usually leans slightly forward, so that it almost rests on top of the bladder. However, in about 20% of women the uterus leans backwards and is referred to as being retroverted. This is quite normal, just an individual difference, and will generally not affect a pregnancy, labour or birth.
The entrance, or opening to the uterus, is called the cervix (meaning 'neck'), and the cervix is often referred to as the 'neck of the womb'. The cervix is approximately 2.5cm long, and extends down into the top of the vaginal canal. The cervix is normally thick, firm and closed and can be felt as a firm, lump deep at the end of the vagina (if you wish to place your finger inside your vagina to do this). At the time of ovulation (when the woman releases an egg) the cervix changes by rising and opening slightly to allow easier passage for the man's sperm. The cervix also produces a stretchy, 'egg-white type' fertile mucous that helps to carry the sperm up into the uterus for conception.
The inner lining of the uterus is a rich and nourishing mucous membrane known as the 'endometrium'. This layer is shed through menstruation (or the woman's periods) and then regenerates after the period finishes, in readiness for the possibility of a fertilised egg implanting in each month. When a woman experiences orgasm, the smooth muscular walls of her uterus move in continuous waves to increase the movement of the sperm to the egg. These movements (or contractions) also increase when the endometrium is shedding during menstruation, and are at their greatest when a woman is in labour.
The fallopian tubes (or 'oviducts') are two narrow, hollow tubes that lead from either side of the top of the uterus, spreading outward and downward towards the ovaries (the ovaries are two almond-shaped organs that produce an egg each month). At the end of both fallopian tubes (nearest the ovaries), there are long, finger-like tentacles (known as 'fimbria'). The fimbrias are not attached to the ovaries, but gently sweep across the ovaries at ovulation to draw the mature egg into the fallopian tubes. Once the egg is inside the fallopian tubes it is moved along towards the uterus by small, hair-like structures (called 'cilia') as well as the muscle fibres in the wall of the tubes producing wave-like contractions.
It is in the fallopian tubes that the man's sperm fertilises the egg, to conceive a baby. The tubes have a rich supply of blood and are filled with cells that secrete a protein-rich fluid to nourish the egg until it reaches the uterus.
The ovaries are two, white almond shaped organs (the equivalent of the male testes). They are positioned on either side of the uterus under the end of each fallopian tube. The ovaries are a woman's storehouse of egg cells. Over the course of an average reproductive lifespan, a woman will produce around 300 - 500 mature eggs for potential conception.
Each month around 20 egg cells begin to ripen. However, only one follicle becomes dominant while the others shrink away. The dominant egg ripens to maturity in one of the ovaries and is released into the fallopian tube. Usually a mature egg will be released from one ovary one month (for example the right ovary) and then the next month the left ovary will produce a mature egg. The release of the egg is called 'ovulation'. If both ovaries release an egg at the same time, then the woman may conceive twins.
Some women are very aware of when they release an egg (or 'ovulate') because they experience a pain on one side of their lower stomach or back. This is called 'Mittelschmerz' meaning 'middle pain'. However, it is now known that Mittelschmerz pain is felt about 24 to 48 hours before the actual release of the egg, because the pain is caused by the egg preparing to be released and not the actual release in itself. If the released egg is not fertilised in the fallopian tube, it will move down into the uterus and be passed with the next menstrual period.
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Last revised: Wednesday, 19 February 2014
This article contains general information only and is not intended to replace advice from a qualified health professional.