Female Reproductive System
How The Female Reproductive System Works

Health Topics


Female Reproductive System


What Is The Female Reproductive System?
How Pregnancy Happens
Diseases and Disorders

Diagrams, Female Body
Menstrual Cycle

What Is The Female Reproductive System?

It is the system that allows for pregnancy in women. Apart from the entrance to the vagina and the vulva, the female reproductive system is hidden inside the body. It consists of the:

Cervix and cervical canal
Uterus (womb)
2 ovaries
2 fallopian tubes
Breasts (accessory organs)

The reproductive organs inside the body are contained and protected by the pelvic girdle (a group of bones, including the hip bones that make up the pelvis). This bony girdle has the same structure in both sexes but is wider in the female in order to allow room for the passage of a baby.

Did You Know?

The female body is capable of producing up to 35 children in an average lifetime.



What Is The Vulva?

The external organs of the female reproductive system are collectively known as the vulva. They include the mons pubis, the labia majora and minora and the clitoris.
Mons pubis: A protective pad of fat over the pubic bone. It is covered in hair after puberty.
Labia majora: 2 large folds of fatty tissue which run lengthways either side of the vulva from the mons pubis to the perineum (skin between the vulva and anus). They protect the entrance to the vagina and urethra (where urine comes out).
Labia minora: 2 smaller folds of skin within the labia majora. They surround the clitoris and form a hood (prepuce) to protect it.
Clitoris: A very small, sensitive organ that is equivalent to the male penis. It even contains erectile tissue like the penis. It is situated just below the mons pubis. During sexual activity the erectile tissues fill with blood and swell. Its only known function is to stimulate sexual pleasure.

What Is The Vagina?

Structure: The vagina is a muscular passage that leads from the vulva to the neck of the womb (cervix). It connects the internal reproductive organs with those on the outside of the body. During sexual activity the blood vessels in the vaginal walls fill with blood causing them to swell and become engorged.
Functions: The vagina connects the cervix to the vulva, and thus to the outside of the body. It serves as a passageway for menstrual blood, forms part of the birth canal during labor and is the site of penetration during intercourse.

What Is The Cervix?

Structure: The cervix is the narrow neck of the uterus which opens into the vagina. Usually it has an opening about the width of a pencil to allow sperm through and period blood out. But during childbirth it dilates to allow the passage of the baby.
Function: The cervix forms the first part of the birth canal. The dilation of the cervix is a measurement used to determine how soon childbirth will begin. It also produces cervical mucus to prevent infections passing from the vagina through to the womb. This mucus changes consistency during the menstrual cycle, becoming more watery when the woman is ovulating and fertile. This is eases the passage of sperm through the cervix so it can travel on and hopefully meet an egg to fertilize.

Uterus (Womb)


What Is The Uterus?

The center of the female reproductive system is the uterus, also known as the womb. It is here that a fertilized egg (ovum) grows into a baby. The top end opens out into the Fallopian tubes (which lead to the ovaries) and the bottom end, or cervix, opens into the vagina and forms the birth canal.
Structure: The uterus is a muscular, hollow organ. It is the size and shape of an upside-down pear, about 7.5cm long and 5cm wide and expands during pregnancy to accommodate the fetus. The lining of the uterus (endometrium) consists of layers of tissues which respond to hormonal secretions. These layers thicken every month ready to act as a nourishing bed for the fertilized egg.

Function: The uterus is the place where the fetus grows and develops. Every month it prepares
itself for a possible pregnancy and if there is no fertilized egg, menstruation occurs (the lining of the womb and unfertilized egg is expelled through the vagina).

What Are The Fallopian Tubes?

Structure: The Fallopian tubes are tubes that connect the uterus and ovaries. They have a funnel-like end with finger-like projections that catch an egg when it is released from an ovary. The egg moves through the fallopian tubes and into the uterus. They are named after the Italian anatomist who discovered them.
Functions: The Fallopian tubes are a passageway from the ovaries to the uterus for the egg, as well as the site of fertilization. Sperm swim up these tubes to reach the egg.

What Are The Ovaries?

Structure: The ovaries are two glands. They are approximately the size and shape of almonds and they are positioned either side of the uterus, just below the fallopian tubes.
Function: The ovaries have two main functions. The first is to secrete the hormones responsible for female sexual characteristics (progesterone and estrogen). The second is to store the female eggs. Unlike sperm (which is produced daily), women are born with all the eggs they will ever have. A newborn baby girl has about 60,000 eggs in her ovaries at birth. These eggs are in an immature form but every egg has the potential to mature and be released for fertilization. In practice, only about 500 eggs mature in a woman’s lifetime. Usually only one egg is released a month during the menstrual cycle.

What Is A Follicle?

These are small structures on the surface of the ovary that contain eggs. Follicles are known as Graafian follicles when they mature. They contain fluid and an egg. As soon as an egg is mature and ready to be fertilized, the follicle splits, releasing the egg which then travels along the Fallopian tube towards the uterus.



What Are The Breasts?

The breasts are accessory organs to the reproductive system. Although not directly involved in the process of reproduction, they develop during pregnancy ready for their function as milk-secreting glands.
Structure: The breasts are glands which sit on the front of the female chest (men also have breasts, but they are undeveloped). Their size varies considerably. Each breast is circular with a central, raised nipple. Breasts consist of fatty tissue supported by connective tissue. Each breast contains about 20 lobes that radiate from the nipple. These lobes subdivide into lobules, which open into several ducts. These ducts open on the surface of the nipple and secrete milk when a mother is breastfeeding. Hormones cause the breasts to grow during puberty and then activate the secretion of milk during pregnancy.

How Pregnancy Happens

Egg is released from the ovary and enters the fallopian tube in the direction of the uterus. It reaches the center of the tube in around 30 minutes. If sperm (in semen) have been deposited in the vagina within 24 hours of ovulation, there is a 3 day window in which fertilization can occur. Several hundred sperm (out of the many million deposited) will have swum through the uterus and into the fallopian tubes in the search for an egg. Only one sperm is needed to fertilize an egg. The successful sperm penetrates the egg's membrane and enters the egg (step 2). This is fertilization.

After Fertilization
The tail of the sperm breaks down and its head or nucleus grows. The nucleus of the sperm and the nucleus of the egg fuse to make a single nucleus. Within this new nucleus, the male and female chromosomes join up forming the zygote, the first cell of a new baby.

Cell Division
Once the zygote has formed, it undergoes a process of mitotic cell division, dividing into two, then 4, then eight cells and so on until a ball of cells, called a morula, is formed (step 3). After 5 days this develops into a blastocyst (a multi-celled structure). The blastocyst enters the uterus and implants in the endometrium (lining) of the uterus on the 7th day (step 4).

Formation of Embryo
By day 24 the blastocyst has formed an amniotic cavity (a fluid-filled sac) containing an embryo that looks a little like a seahorse. The endometrium and part of the blastocyst mesh develop into the placenta, the baby's support system (which allows the passage of nutrients, oxygen and waste to and from baby and mother).

Development of Fetus
The embryo is known as the fetus from 8 weeks. It develops in the amniotic cavity. The fluid protects the baby from shocks and pressure and allows it to grow unhindered.

Just before birth, the membrane of the amniotic cavity breaks and the amniotic fluid is released via the vagina (known as your water breaking). Childbirth usually occurs in the 40th week after fertilization.

Diseases And Disorders Of The Reproductive System

Check your symptoms: Reproductive disorders, symptom checker


Absence of periods
Amenorrhea. This can be caused by a hormone imbalance, stress, radical weight loss or excessive exercise.
Painful periods
Dysmenorrhea. This can be caused by hormone imbalances or stress.
Heavy periods
Menorrhagia. Soaking a pad or tampon every hour or bleeding for more than 7 days.
Irregular periods
Oligomenorrhea. More common in the first 5 years after menarche and again when approaching menopause. May also be a sign of a hormone imbalance caused by PCOS.
Pre-menstrual syndrome: Tiredness, bloating, irritability and depression you feel a few days before your period is due.
Severe PMS
Premenstrual dysphoric disorder: PMS symptoms that are so severe you need to miss school or work.
Toxic shock syndrome
Rare but deadly bacterial infection that was caught through the use of older brands of tampons.


Polycystic ovarian syndrome
PCOS is a condition causes irregular periods, multiple fluid filled blisters to form on the ovaries, difficulties getting pregnant and skin problems like acne.
The presence of menstruation tissue elsewhere other than the lining of the uterus. Causes painful periods and infertility.
A non-cancerous tumor in the uterus that grow outside, inside or within the wall of the uterus (womb).
Breast fibroids
Benign tumors that grow inside the breasts. Some can be solid tissue, others are fluid filled cysts.
Yeast Infections
Over-growth of yeast fungus in the vagina. Causes itching, white cottage cheese discharge and soreness around the vulva and vagina.
Inflammation of the vagina caused by infection. There may be burning or itching around the vagina and a strong smelling discharge.
Painful intercourse
Vaginal pain during or after sexual intercourse, also called dyspareunia (painful intercourse).
Vulva Pain
Pain or discomfort in the vulvar area that lasts more than 3 months may be diagnosed as vulvodynia.
Inflammation of the vulva. It is not a condition itself but rather a symptoms of other problems such as vaginitis or yeast infection.
Uterine Polyps
Benign, non-cancerous growths that grow inside the uterus (womb). Although they are rarely cancerous, they should be removed just in case.
Cervical Polyps
Fingerlike fleshy growth on the cervix. Rarely cancerous, but they should be removed just in case.
Pelvic inflammatory disease
A bacterial infection that damages the organs in the reproductive system leading to pelvic pain, ectopic pregnancy and infertility.
Ovarian cysts
Fluid filled cysts that form on the ovaries. Some remain small, while others can grow to the size of an orange.


Ectopic pregnancy
This is a pregnancy which occurs outside the uterus. A fertilized egg may develop inside the fallopian tube instead of traveling to the uterus. There is a danger of hemorrhage and death.
Ovarian tumors in pregnancy
Cancer of the ovaries discovered in pregnancy. While rare, early treatment is critical.

After Childbirth

Postpartum complications
List of potential complications that can occur after childbirth.
Postpartum bleeding
After childbirth the lining of the uterus is shed over 3 to 6 weeks in the form of vaginal bleeding called lochia.
Painful breast infection that affects women who breastfeed.
The inability to conceive after a year of regular sexual intercourse without protection.


Breast cancer
Breast cancer is one of the most feared diseases in America. It strikes over 180,000 women a year, killing about 40,000.
Cervical cancer
Cancer which starts in the cervix. Screening for signs of cervical cancer is done by Pap smear test.
Endometrial cancer
Cancer that starts in the womb. It accounts for about 6 percent of all new female cancers and affects 39,000 American women a year.
Ovarian cancer
Cancer that starts in the ovaries. Every year there are about 22,000 new cases of ovary cancer diagnosed in the United States and about 15,000 related deaths.
Vaginal cancer
Cancer of the vagina is very rare and accounts for less than 2 percent of all gynecologic cancers in America. In 2011 there were just over 2,500 new cases and 780 deaths attributed to the disease.
Vulva cancer
Cancer of the vulva is very rare and accounts for 1 percent of all cancers in American women. This amounts to about 4,000 new cases being diagnosed every year.
Fallopian tube cancer
Cancer that starts in the fallopian tubes. It is very rare, in total only about 1500 cases have been recorded in America since records were started in 1847.

Sexually Transmitted Diseases

Common bacterial infection that is the leading cause of PID and infertility.
Genital Herpes
Painful sores in the genital region. There is no cure and patients can suffer outbreaks for years.
Bacterial infection which if untreated can gradually cause major organ failure.
Genital Warts
Benign growths on the genitals that are easily spread from one partner to the other.
Bacterial infection that can cause a genital sore. Only a handful of cases are reported every year in the U.S.
Parasite infection that causes a smelly, green frothy vaginal discharge.
HPV infection
Human Papilloma Virus (HPV) is a common STD, it is the leading cause of cervical cancer.
Highly contagious infection where tiny mites burrow under the skin and deposit their eggs and feces. Scabies causes agonizing itching, particularly at night.
Pubic lice
Also called crabs, these are lice that live in the pubic hair and cause agonizing itching.

Other Useful Guides

Gynecological disorders: Common problems women experience 'down there'.
Recommended health screenings for women: Smear tests, and more.
Estrogen and what it does: Effects on the female body.
Muscles of the body: System and how it works.
Endocrine system: Hormones and what they do to the body.
Development of the female body: From puberty to adulthood.

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