The female reproductive system The Mammary Glands The mammary glands are accessory organs of the female reproductive system that are specialized to secrete milk following pregnancy. They are located in the subcutaneous tissue of the front thorax within the elevations which are called breasts. A �nipple� is located near the tip of each breast, and it is surrounded by a circular area of pigmented skin called the �areola.� A mammary gland is composed of fifteen to twenty irregularly shaped lobes, each of which includes alveolar glands, and a duct (lactiferous duct) that leads to the nipple and opens to the outside. The lobes are separated by dense connective tissues that support the glands and attach them to the tissues on the underlying pectoral muscles. Other connective tissue, which forms dense strands called �suspensory ligaments,� extends inward from the skin of the breast to the pectoral tissue to support the weight of the breast. The breasts are really modified sweat glands, which are made up of fibrous tissues and fat that provide support and contain nerves, blood vessels and lymphatic vessels. Cervix The lower one-third of the uterus is the tubular �cervix,� which extends downward into the upper portion of the vagina. The cervix surrounds the opening called the �cervical orifice,� through which the uterus communicates with the vagina. Fallopian Tubes The fallopian tube extends from the uterus to the ovary. This tube carries eggs and sperm and is where fertilization of the egg, or �ovum� takes place. The fallopian tubes lie in the pelvic portion of the abdominal cavity and each tube reaches from an ovary to become the upper part of the uterus. This funnel-shaped tube is about three inches in length. The larger end of the funnel is divided into feathery, finger-like projections which lie close to the ovary. These beating projections, along with muscle contractions, force the ovum down the funnel small end, which opens into the uterus. After sexual intercourse, sperm swim up this funnel from the uterus. The lining of the tube and its secretions sustain both the egg and the sperm, encouraging fertilization and nourishing the egg until it reaches the uterus. If an egg splits in two after fertilization, identical or �maternal� twins are produced. If separate eggs are fertilized by different sperm, the mother gives birth to un-identical or �fraternal� twins. Labia Minor The labia (singular, labium) minor are flattened lengthwise into folds located with the cleft between the labia major. These folds extend along either side of the vestibule. They are composed of connective tissue that is richly supplied with blood vessels, causing a pinkish appearance. In the back, near the anus, the labia minor merge with the labia major, while in the front they converge to form a hood-like covering around the clitoris. Ovary Ligaments Each ovary is attached to several ligaments that help to hold it in position. The largest of these, formed by a fold of peritoneum, is called the �broad ligament.� It is also attached to the uterine tubes and to the uterus. At its upper end, the ovary is held by a small fold of peritoneum, called the �suspensory ligament,� which contains the ovarian blood vessels and nerves. At its lower end, it is attached to the uterus by a rounded, cord-like thickening of the broad ligament, called the �ovarian ligament.� The �peritoneum� is a two-layered membrane that supports the abdominal organs, produces lubricating fluid that allows the organs to flow smoothly over each other, and protects against infection. Ovaries The ovaries are a pair of oval or almond-shaped glands which lie on either side of the uterus and just below the opening to the fallopian tubes. In addition to producing eggs or �ova,� the ovaries produce female sex hormones called estrogen and progesterone. The ovaries produce a female hormone, called estrogen, and store female sex cells or �ova.� The female, unlike the male, does not manufacture the sex cells. A girl baby is born with about 60,000 of these cells, which are contained in sac-like depressions in the ovaries. Each of these cells may have the potential to mature for fertilization, but in actuality, only about 400 ripen during the woman lifetime. Pregnant and prenatal both come from the same Latin roots. �Prae� means �before� and �nascor� means �to be born�. Nascor is also the derivative of nature, innate and native. Only a few years ago, the word, �pregnant� was seldom used in mixed company. Polite society referred to a pregnant woman as �expecting� or �being in the family way.� Uterus The uterus or �womb� is a hollow, muscular organ in which a fertilized egg, called the �zygote,� becomes embedded and in which the egg is nourished and allowed to develop until birth. It lies in the pelvic cavity behind the bladder and in front of the bowel. The uterus usually tilts forward at a ninety degree angle to the vagina, although in about 20%% of women, it tilts backwards. The uterus is lined with tissues which change during the menstrual cycle. These tissues build under the influence of hormones from the ovary. When the hormones withdraw after the menstrual cycle, the blood supply is cut off and the tissues and unfertilized egg are shed as waste. During pregnancy, the uterus stretches from three to four inches in length to a size which will accommodate a growing baby. During this time, muscular walls increase from two to three ounces to about two pounds and these powerful muscles release the baby through the birth canal with great force. The womb shrinks back to half its pregnant weight before a baby is a week old. By the time the baby is a month old, the uterus may be as small as when the egg first entered. Superstition, myth or ignorance have surrounded the menstrual period since the beginning of time. This is largely due to a primitive fear of blood. The word, �taboo,� may stem from the Polynesian word for menstruation, but not all legends are negative; a girls first menses is celebrated in some societies, because it is a sign that she can bear children. Vagina The vagina is a muscular passage which forms a part of the female sex organs and which connects the neck of the uterus (called the �cervix�) with the external genitals. The vagina, which is approximately two and one-half to four inches long, has muscular walls which are supplied with numerous blood vessels. These walls become erect when a woman is aroused as extra blood is pumped into these vessels. The vagina has three functions: as a receptacle for the penis during love-making; as a outlet for blood during menstruation; and as a passageway for the baby to pass through at birth. According to The Guiness Book of World Records, a Russian peasant woman who lived in the 18th Century holds the record for the most children born to one mother. She had sixty-nine children within forty years. She produced sixteen pairs of twins, seven sets of triplets, and four sets of quadruplets! Vulva The vulva is made up of several female organs which are external. These include a small, rounded pad of fat which protects the pubic bone. Reaching down almost to the anus are two folds of fatty tissue, called the �larger lips,� to protect the inner genitals. Just inside are two �smaller lips,� which enclose the opening of the urethra (which comes down from the bladder) and the vagina. At the upper end, are small projections, called the �prepuce,� that protect the clitoris. The clitoris is a very small, sensitive organ with numerous nerve endings that, like the penis, contain tissues which fill with blood when sexually aroused.