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The female genital organs consist of an internal and an external group.
The external genital organs include the mons pubis, labia majora, labia minora, Bartholin's glands, and clitoris. The area containing these organs is called the vulva. At the beginning of vulva, just inside the opening of the vagina, is the hymen, a mucous membrane. In virgins, the hymen usually encircles the opening like a tight ring, but it may completely cover the opening.
The hymen helps protect the genital tract but is not necessary for health. It may tear at the first attempt at sexual intercourse, or it may be so soft and pliable that no tearing occurs. The hymen may also be torn during exercise or insertion of a tampon or diaphragm. Tearing usually causes slight bleeding. In women who have had intercourse, the hymen may be unnoticeable or may form small tags of tissue around the vaginal opening.
The external genital organs have three main functions:
• Enabling sperm to enter the body
• Protecting the internal genital organs from infectious organisms
• Providing sexual pleasure
The internal genital organs form a pathway (the genital tract).
This pathway consists of the following:
• Vagina, where sperm are deposited and from which a baby can emerge
• Uterus, where an embryo can develop into a fetus
• Fallopian tubes (oviducts), where a sperm can fertilize an egg
• Ovaries, which produce hormones and release eggs
Sperm can travel up the tract, and eggs down the tract.
Vagina is a narrow, muscular but elastic organ about 4 to 5 inches long in an adult woman. It connects the external genital organs to the uterus. The vagina is the main female organ of sexual intercourse. It is the passageway for sperm to the egg and for menstrual bleeding or a baby to the outside.
Vagina is lined with a mucous membrane, kept moist by fluids oozing from cells on its surface and by secretions from glands in the cervix (the lower part of the uterus). A small amount of these fluids may pass to the outside as a clear or milky white vaginal discharge, which is normal. During a woman's reproductive years, the lining of the vagina has folds and wrinkles.
Before puberty and after menopause (if the woman is not taking estrogen), the lining is smooth.
Uterus is a thick-walled, muscular, pear-shaped organ located in the middle of the pelvis, behind the bladder, and in front of the rectum. The uterus is anchored in position by several ligaments. The main function of the uterus is to sustain the developing fetus. The uterus consists of the cervix and the main body (corpus). Women are able to feel the cervix by introducing a finger inside the vagina.
Sperm can enter and menstrual blood can exit the uterus through a channel in the cervix. The channel is usually narrow, but during labor, the channel widens to let the baby through. The cervix is usually a good barrier against bacteria, except around the time an egg is released by the ovaries (ovulation), during the menstrual period, or during labor. Bacteria that cause sexually transmitted diseases can enter the uterus through the cervix during sexual intercourse.
The uterus endometrial cavity has a very special covering called endometrium. During period/menstruation most of the endometrium is shed leaving just a residual basal layer which regenerates the endometrium during each menstrual cycle. The endometrium has the ability to allow an early embryo to become implanted and to receive nourishment before the placenta (afterbirth) develops.
Fallopian tubes extend for about 10 cm from each side of uterus, outwards to their openings near the ovaries. At their openings there are very fine finger-like fronds called fimbria. The inner surface of the tubes have fine hair-like structures called cilia which help to move eggs, released from the ovaries, along the tubes and into the cavity of the uterus.
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Ovaries release eggs and female sex hormones. Usually baby girl is born with egg cells (oocytes) in her ovaries. Between 16 and 20 weeks of pregnancy, the ovaries of a female fetus contain 6 to 7 million oocytes. Most of the oocytes gradually waste away, leaving about 1 to 2 million present at birth. None develop after birth. At puberty only about 300 000 remain. Only small proportions of oocytes reach the maturity and produce the eggs. Approximately 400 eggs are released during each woman's reproductive life - usually one during each menstrual cycle. Only mature eggs are able to develop the normal pregnancy. Several thousands of oocytes do not reach the maturity and they usually degenerate. Degeneration progresses are faster before menopause (in the 10-15 years before menopause). All oocytes are gone by menopause.
Ovaries produce mainly female sex hormones - estrogen and progesterone; and a small proportion of male sex hormones. During some diseases ovaries can produce high level of male hormones (mainly during PCOS).
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