Merck Manual

Please confirm that you are not located inside the Russian Federation

honeypot link

Female Reproductive System


The Manual's Editorial Staff

Reviewed/Revised Apr 2022 | Modified Sep 2022
Get the full details
Topic Resources

What is the female reproductive system?

The female reproductive system is the system in a woman's body with the purpose of making babies. The female reproductive system includes both external genital organs (outside the body) and internal genital organs (inside the body).

The external genital organs include:

  • Labia: Two sets of skin folds that cover the opening to the vagina

  • Clitoris: Organ where the labia meet that feels pleasure during sex

  • Opening to the vagina

Not all of your external genitals are your "vagina." The vagina is really just the birth canal.

The internal genital organs include:

  • Vagina: Birth canal

  • Uterus (womb): The internal organ where a fetus grows and develops before birth

  • Cervix: The thick, round end of the uterus, which has an opening for menstrual blood to flow out and for a baby to be delivered

  • Ovaries: A pair of organs that make eggs and female hormones such as estrogen

  • Fallopian tubes: The tubes through which eggs pass from the ovaries to the uterus

External Female Genital Organs

External Female Genital Organs

Internal Female Genital Organs

Internal Female Genital Organs
Overview of the Female Reproductive System

How does the female reproductive system work?

The main activities of the female reproductive system include:

A newborn girl's ovaries already have all the eggs she will ever have. But these eggs can't become babies until the girl's reproductive system goes through a series of changes called puberty Puberty in Girls Puberty is the period of growth and development in which children and adolescents develop adult physical features, such as breasts or pubic hair, and become able to reproduce (have and create... read more . During puberty:

  • Hormones (chemical messengers) released by the brain cause the ovaries to develop

  • The developing ovaries release the female sex hormone estrogen

  • Estrogen causes the rest of the reproductive system to develop

  • An egg matures and is released (a process called ovulation)

  • The lining of the uterus swells up with blood vessels so it's ready to accept the egg if it gets fertilized by a man's sperm

  • A fertilized egg attaches to the lining of the uterus and starts growing OR

  • The egg doesn't get fertilized, so it doesn't attach, and the lining of the uterus comes off and is released as menstrual blood

If a woman doesn't become pregnant, the menstrual cycle repeats about once a month. Women have a menstrual cycle until about middle age. Menopause Menopause Menopause is when women stop having periods (stop menstruating) and can no longer get pregnant. Menopause usually happens after age 40. In the United States, the average age for menopause is... read more Menopause is when the cycles stop.

Conception is when a man's sperm joins with (fertilizes) a woman's egg. Fertilization usually happens in one of the fallopian tubes.

  • The fertilized egg travels down the fallopian tube into the uterus

  • The fertilized egg attaches to the inside wall of the uterus and starts growing

  • It grows into a fetus and a placenta—the placenta is what attaches the fetus to the uterus

The reproductive system is controlled by hormones. Hormones are chemical messengers made in certain parts of your body that travel through the blood to signal other parts of the body what to do.

Some hormones come from the pituitary gland in the brain. Reproductive hormones from the pituitary gland rise and fall each month and trigger the menstrual cycle. If you become pregnant, your reproductive organs produce other hormones that turn off your menstrual cycle and signal the uterus to grow and support the baby. After birth, another hormone signals your breasts to make milk to feed your baby.

What can go wrong with a woman's reproductive system?

The most common problems with the reproductive system involve hormones. A woman's reproductive system involves many hormones that work together in complicated ways. Many different problems can interfere with the hormones, which can result in:

  • Delayed puberty

  • Early puberty

  • Irregular menstrual periods

  • No menstrual periods

  • Inability to get pregnant

  • Trouble keeping a pregnancy

Many diseases, such as infections and cancer, can affect the reproductive organs.

quiz link

Test your knowledge

Take a Quiz!