The Female Reproductive System


Each woman is born with two ovaries that are positioned in her pelvis. These oval-shaped organs produce one egg per month in response to the woman’s monthly cycle of hormones. Generally, one ovary produces one egg one month and the other ovary produces an egg the next month. There are exceptions to this general rule. A few women inherit a disposition to release multiple eggs during a cycle. If these eggs get fertilized, the children born are fraternal twins. Identical twins are the result of a single fertilized egg dividing, early in development, into two children. A woman past the age of 30 is more likely to give birth to twins than a younger woman. The drugs used to treat infertility in women can also cause the release of multiple eggs.

The official name for the female egg is an ovum. Each ovum is stored in compartments in the ovaries which are called ovarian follicles. A woman is born with all the ovum she will ever have – about 200,000 in each ovary. No additional eggs are produced during a woman’s life. During her lifetime, a woman will typically release 400 to 500 eggs.

The eggs are released by breaking out of the outer edge of the ovary. Usually, this minute wound, called a cyst, heals without any discomfort, but a few women experience discomfort. Some only experience discomfort when they become pregnant. The hormones released because of pregnancy interfere with the healing process. This condition is known as having a cyst of pregnancy.

The ovaries are also the source of female hormones called estrogens. The hormones vary on a roughly monthly cycle. The variation of the hormones regulates when an egg is released, gives time for the fertilized egg to grow, or flushes the lining of the uterus if there is not fertilized egg present.

Fallopian Tubes

Near each ovary is a small, thin tube called the fallopian tube. The end near the ovaries fans out into finger-like extensions called fimbria. These fingers collect the egg when it is released and directs it down the fallopian tube. It takes several days for the egg to move through the tube. It is in the fallopian tube where the sperm meets the eggs and fertilization occurs.

The internal diameter of the tube is very narrow, and in rare instances, a fertilized egg may not make it through the tube to the uterus. Instead, the child begins to develop within the tube. This is known as a tubal pregnancy. In such cases, the woman will experience sharp pains in her abdomen. The fallopian tubes do not have the capacity to hold a growing baby. If something is not done quickly, the tubes will burst and the mother will bleed to death internally. Fortunately, such events are rare, but any woman who could have become pregnant and experiences abdominal pain needs to see her doctor as quickly as possible.


The uterus is a pear-shaped, muscular organ about the size of a fist. It has the ability to stretch many times its size and it is designed to hold a developing child. Each month, prior to an egg being released from an ovary, a blood-rich lining forms on the interior of the uterus. If a fertilized egg becomes imbedded in the lining, it provides the nutrients for the child to grow. If the egg is not fertilized, the lining is sloughed off. It is the shedding of the endometrium lining that causes a woman’s monthly blood flow.

A woman’s body matures enough to allow a pregnancy to take place shortly before the time of her first menstrual period. However, all the support systems necessary to permit a child to fully develop are not in place for several more years. This is why girls who become pregnant before the age of 16 have a 40-times greater risk of dying during childbirth. They are also more likely to give birth to premature babies. A woman should wait until she is fully developed (around the age of 18) before she marries and begins to have children.


The cervix is the narrow opening, about the diameter of a pencil, at the bottom of the uterus. Normally cervix remains open. However, when a child begins to develop in the uterus, a mucus plug forms in the cervix, which helps to isolate the developing child from diseases. As the time for birth approaches, the cervix begins to open. Doctors measure the diameter of the opening to estimate how soon the child will be born. Just before birth, the cervix will widen to 10 centimeters.


The vagina is an elastic tube which connects the uterus to the outside world. It contains many folds which allow it to change both diameter and length. Normally the vagina is about 3 to 4 inches in length. During sexual intercourse, the uterus tilts and the vagina lengthens to accommodate the husband’s penis. This is a learned response. It typically takes several months before the wife’s body automatically makes the appropriate adjustments.

The vagina, which is normally about an inch in diameter, must stretch wide enough to allow a baby to pass through during birth. After birth, it takes a few weeks for the vagina to regain its normal size. Kegel exercises help to restore the size of the vagina. This same exercise also enhances the sexual experience. To locate the proper muscles, attempt to stop the flow of urine when you using the restroom. Once you are able to start and stop the urine flow by conscience thought, note the muscles you are using. During the day, tighten and relax the muscles for about three seconds ten times in a row. Your aim is to eventually reach the point where you can do ten sets during the day (though they do not need to be done all at once).

Glands line the vagina which produces a lubricating fluid during sexual stimulation. This lubrication is essential for the woman’s enjoyment of intercourse. The lubricating fluid allows the husband’s penis to move in and out of the vagina smoothly. Without the fluid, the walls of the vagina become irritated and can tear. It takes about 10 minutes of sexual foreplay for a wife to produce enough lubricating fluid to make intercourse enjoyable. Stress or anxiety can interfere with the production of these fluids. Also, just prior to the wife’s next menstrual cycle, these glands do not function well. For these times, a small tube of water-based lubricants, such as K-Y Jelly, is handy to have on hand. Do not use an oil or petroleum-based lubricant as they will irritate the lining of the vagina.


Every woman is born with a thin membrane that partially covers the vaginal opening. The amount of coverage varies widely from one woman to the next. It is never completely covered, else there would be no place for the blood from the monthly menstrual periods to flow. The hymen is located about an inch inside the vulva at the entrance to the vagina.

Generally, most women’s hymen remains intact until their first experience of sexual intercourse. Because the penis is too large to fit through the opening (or openings) in the hymen, intercourse will tear the hymen, causing a small amount of pain and a small amount of bleeding. Evidence of this bleeding was one way people proved that a woman was a virgin when she married (Deuteronomy 22:13-21). Not all women bleed during their first experience at sex. These women might have been born with a small hymen, or the hymen may have been torn in the past such as during a vaginal exam by a doctor or by the careless use of tampons.


The vulva is the outer opening of the female reproductive system. It consists of two sets of lips. The outer lips are called the labia majora (major lips). They protect the access to the reproductive system. The pubic hair of a woman grows on the outer surface of the major lips, which is called the mons veneris. The inner lips are called the labia minora (minor lips). They are composed of softer tissue.

During sexual foreplay, arousal causes the major lips to swell and part. As sexual stimulation continues, the minor lips also swell and part. Both lips will increase to two or three times their normal thickness. This swelling not only gives access to the vagina, but it also narrows the diameter of the opening. This “grips” the shaft of the penis providing additional stimulation for the husband and the wife as the penis is moved in and out of the vagina.


The clitoris is a very small organ located between the major and minor lips of the vulva, near the top where the two sides of the lips come together. The clitoris is about the size of a pea and is packed with highly sensitive nerve endings. The sole purpose of the clitoris is to give pleasure to the woman during sexual intercourse. Stimulation of the clitoris is necessary for a woman to reach orgasm.

A small flap of skin, known as the hood, covers the clitoris. When a woman becomes aroused, the hood withdraws, leaving the clitoris exposed to stimulation by touch. Actually, the clitoris is so sensitive, that any movement of the skins of the major or minor lips produces a pleasurable feeling in the woman. Direct or heavy stimulation of the clitoris is usually uncomfortable, much like the difference between a light touch on the skin versus a hard, heavy rub on the skin.


The breasts are the most noticeable part of the female anatomy. They contain milk glands, called mammary glands, which are surrounded by fatty tissue. Each breast has a dark area of skin called the areola which is sensitive to touch and temperature. In the center of each areola is a nipple.

The primary purpose of the breast is to provide milk for newborn infants. However, the breasts also produce pleasurable feelings when touched so they are also involved in sexual intercourse (Proverbs 5:19; Isaiah 66:11).

The size and shape of a woman’s breasts are determined by genetics. Regardless of a breast’s shape or size, they still function in the same manner. A woman’s breast size also varies over time. The most noticeable change comes during adolescence when the breasts first develop. However, they also change size in response to a woman’s monthly menstrual cycle. The changing hormones cause changes in the amount of water the female body holds in reserve, which in turn affects the size of a woman’s breasts. Since the breasts are mostly composed of fat tissue, any changes in a woman’s weight will also be noticeable in her breasts. When a woman becomes pregnant, the breasts expand as they gear up for milk production. Finally, as a woman ages, her skin loses its elasticity and frequently the breasts will begin to sag.

Breast cancer is a concern for older women. Each woman should check her breasts once a month, shortly after her period has ended. She should squeeze and massage her breasts to locate any lumps or swellings that have appeared since the previous month. The reason for examining the breasts after her period is that temporary lumps sometimes appear due to the changing hormones. By examining the breasts at a consistent time during the monthly menstrual cycle, a woman is less likely to confuse a temporary swelling for a significant change.

While examining the breasts, a woman should squeeze her and look for any discharge or liquid from them. Unless a woman is pregnant or breastfeeding, her breasts should not be producing any liquid.


Each month, a woman’s body goes through a cycle of changes known as the menstrual cycle. The cycle begins in the teenage years and continues until a woman is in her fifties. When the monthly cycles have ended, called menopause, a woman is no longer able to have children.

The number of days in a menstrual cycle will vary. For younger women, the cycles tend to be more erratic and longer in duration. Generally, by the time a woman reaches her twenties, the cycles settle down to an average length of 28 days. However, at times a woman’s cycle can be as short as 14 days or as long as 32 days. Some very slim women or athletic women may skip a period. This is not a cause of concern unless it happens several months in a row.

Under the Old Testament Law, Israelite women were considered unclean during their menstrual period. Once her blood started flowing, she had to keep herself separated from other people for seven days (Leviticus 15:19-25). Anything she sat on or laid on were also considered unclean and any person touching these things would be unclean until evening. If her husband had sex with his wife during her period, he became unclean for seven days (Leviticus 15:24; 18:19; 20:18).

The laws of uncleanness taught the Israelites the nature of sin through physical examples. While breaking laws is sin, most of the events declared to be unclean were not sinful in and of themselves. For example, pigs are not sinful, but it was considered unclean (and sinful) to eat pork under the Law of Moses. Most of the things God selected as unclean are things we recognize today as common-sense health regulations – especially for a society that did not understand the full nature of diseases and their spread. So while the primary purpose of the laws was to teach the people about the nature of sin, these same laws had a secondary effect of improving the health of the Israelite nation.

What Israel learned was that sin has consequences. Some of these consequences come from choice, such as the eating of pork, but others come from natural events over which a person has no choice, such as a woman’s monthly menstruation or a man’s nocturnal release of semen (Leviticus 19:16-18). Since everyone must experience things they have no control over, everyone was forced to learn these lessons. Another lesson that was taught is that sin and its consequences spread, even to those not directly involved in sin.

Some complain that God was unfair to women because she was unclean every month for seven days. They also point out that the birth of a girl required a longer period of separation than the birth of a boy (Leviticus 12:1-5). What is overlooked is that a man was unclean for one day after he released semen. Since this can and often happens multiple times during a month, it is possible for a man to be unclean for more than seven days during a month. In addition, since a boy child was to be circumcised on the eighth day, this additional flow of blood from the operation was considered a partial “payment” for the birth.

Since people did not have disposable sanitary napkins in those days, blood touched anything a woman sat or lied upon. Such places became potential breeding grounds for germs. If you read the regulations carefully, you will notice that each period of uncleanness ended with the washing of unclean objects and the person. The laws of uncleanness caused the Israelites to bathe frequently and clean things regularly. Isolation, during times when the risk of disease was high, reduced the spread of disease, keeping the health of the Israelites better than the general population.

The laws of uncleanness passed away with the rest of the Old Testament (Colossians 2:13-17). You do not have to separate yourself during your menstruation. However, the ideas of cleanliness to reduce diseases still make sense today. We still encourage women to change their pads or tampons frequently and to bathe often. It is just common-sense.

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