Female Reproductive System: interactive diagramInternal / External Body Diagrams: interactiveVulva - The external genital organs of the female. The vulva has many major and minor anatomical structures.
Vagina - The human vagina is an elastic muscular canal that extends from the cervix to the vulva. The word vagina is quite often incorrectly used to refer to the vulva or female genitals generally; strictly speaking, the vagina is a specific internal structure.
Labium (plural labia) - A Latin-derived term meaning "Lip". Labium and its derivatives (including labial, labrum) are used to describe any lip-like structure, but in the English language, labium often specifically refers to parts of the vulva.
Clitoris - A sexual organ that is present only in female mammals. In humans, the visible button-like portion is located near the anterior junction of the labia minora, above the opening of the urethra and vagina.
In humans, the clitoris is the most sensitive erogenous zone of the female, the stimulation of which may produce sexual excitement and clitoral erection; its continuing stimulation may produce sexual pleasure in the female and orgasm, and is considered the key to females' sexual pleasure.
Clitoral Hood - In female human anatomy, the clitoral hood is a fold of skin that surrounds and protects the
clitoral glans. It develops as part of the labia minora and is homologous with the foreskin in male genitals.
Hymen - A fold of mucous membrane that surrounds or partially covers the external vaginal opening. It forms part of the vulva, or external genitalia. Despite this, it is not possible to confirm with 100% certainty that a woman is a virgin by examining her hymen. In cases of suspected rape or sexual abuse, a detailed examination of the hymen may be carried out; but in rare instances the condition of the hymen alone is often inconclusive or open to misinterpretation, especially if the patient has reached puberty.
Perineum - The region of the body inferior to the pelvic diaphragm and between the legs. It is a diamond-shaped area on the inferior surface of the trunk which includes the anus and, in females, the vagina. Its definition varies: it can refer to only the superficial structures in this region, or it can be used to include both superficial and deep structures. It is an erogenous zone for both males and females.
A wide variety of slang terms are commonly used for this area of the human body, but they generally refer to a smaller, less inclusive area -- just the surface skin region between the anus and the penis or vagina.
Urethra - A tube that connects the urinary bladder to the outside of the body. In females, the urethra is shorter and emerges above the vaginal opening.
The external urethral sphincter is a striated muscle that allows voluntary control over urination.
Cervix (or neck of the uterus) - The lower, narrow portion of the uterus where it joins with the top end of the vagina. It is cylindrical or conical in shape and protrudes through the upper anterior vaginal wall. Approximately half its length is visible with appropriate medical equipment; the remainder lies above the vagina beyond view.
Vaginal Mucus - A natural substance occurring within the vagina, particularly the cervix, that maintains a certain level of moisture at all times.
The volume, color, and consistency of vaginal mucus changes according to the period of the menstrual cycle. Both the chemical make-up and the physical consistency (viscosity) change during this time. A slippery, clear, egg white-like consistency usually indicates that the woman is ovulating. Relative dryness usually indicates an infertile point in the menstrual cycle.
Excessive or oddly coloured mucus may indicate various infections of the vagina, or pregnancy.
Uterus (or womb) - A major female hormone-responsive reproductive sex organ of most mammals including humans. One end, the cervix, opens into the vagina, while the other is connected to one or both fallopian tubes, depending on the species. It is within the uterus that the fetus develops during gestation, usually developing completely in placental mammals such as humans.
Endometrium (or
Uterine Lining) - The inner membrane of the mammalian uterus. During the menstrual cycle, the endometrium grows to a thick, blood vessel-rich, glandular tissue layer as it undergoes cyclic regeneration. If there is inadequate stimulation of the lining, due to lack of hormones, the endometrium remains thin and inactive.
In humans, the cycle of building and shedding the endometrial lining lasts an average of 28 days. Its formation is sometimes affected by seasons, climate, stress, and other factors. The endometrium itself produces certain hormones at different points along the cycle. This affects other portions of the reproductive system.
Endometriosis is the growth of endometrial tissue outside the uterus.
Endometrial cancer is the most common cancer of the human female genital tract.
Fallopian Tubes - Two very fine tubes lined with ciliated epithelia, leading from the ovaries of female mammals into the uterus. The egg passes through it in a woman's body.
Ovary - An egg-producing reproductive organ, often found in pairs as part of the vertebrate female reproductive system. Ovaries in females are homologous to testes in males, in that they are both gonads and endocrine glands.
Ovaries are oval shaped and, in the human, about the size of a Greek olive.
The ovaries aren't attached to the fallopian tubes but to the outer layer of the uterus via the ovarian ligaments. Usually each ovary takes turns releasing eggs every month; however, if there was a case where one ovary was absent or dysfunctional then the other ovary would continue providing eggs to be released.
Ovaries secrete both estrogen and progesterone.
Ovarian Follicle - The basic units of female reproductive biology, each of which is composed of roughly spherical aggregations of cells found in the ovary. They contain a single oocyte (aka ovum or egg). These structures are periodically initiated to grow and develop, culminating in ovulation of usually a single competent oocyte in humans. These eggs/ova are only developed once every menstrual cycle (e.g. once a month in humans).
Ovulation - The process in a female's menstrual cycle by which a mature ovarian follicle ruptures and discharges an ovum (egg). The time immediately surrounding ovulation is referred to as the ovulatory phase.
The process of ovulation is controlled by the hypothalamus of the brain and through the release of hormones. During the luteal (post-ovulatory) phase, the ovum will travel through the fallopian tubes toward the uterus. If fertilized by a sperm, it may perform implantation there 6–12 days later.
In humans, the few days near ovulation constitute the fertile phase. The average time of ovulation is the fourteenth day of an average length (twenty-eight day) menstrual cycle. It is normal for the day of ovulation to vary from the average, with ovulation anywhere between the tenth and nineteenth day being common.
Menstrual Cycle - A cycle of physiological changes that can occur in fertile females. Overt menstruation (where there is blood flow from the uterus through the vagina) occurs primarily in humans and close evolutionary relatives such as chimpanzees.
The menstrual cycle, under the control of the
endocrine system, is necessary for reproduction. It is commonly divided into three phases: the follicular phase, ovulation, and the luteal phase. The length of each phase varies from woman to woman and cycle to cycle, though the average menstrual cycle is 28 days. Menstrual cycles are counted from the first day of menstrual bleeding. Hormonal contraception interferes with the normal hormonal changes with the aim of preventing reproduction.
Under the influence of progesterone, the endometrium (uterine lining) changes to prepare for potential implantation of an embryo to establish a pregnancy. If implantation does not occur within approximately two weeks, the corpus luteum will involute, causing sharp drops in levels of both progesterone and estrogen. These hormone drops cause the uterus to shed its lining in a process termed menstruation.
In the menstrual cycle, changes occur in the female reproductive system as well as other systems (which lead to breast tenderness or mood changes, for example).
The end of a woman's reproductive phase is called the
menopause, which commonly occurs somewhere between the ages of 45 and 55.
Hormone - A chemical released by a cell in one part of the body, that sends out messages that affect cells in other parts of the organism. Only a small amount of hormone is required to alter cell metabolism. Hormones in animals are often transported in the blood.
Estrogen - A group of
steroid compounds, named for their importance in the estrous cycle, and functioning as the primary female sex hormone.
Like all steroid hormones, estrogens readily diffuse across the cell membrane.
The three major naturally occurring estrogens in women are estrone, estradiol, and estriol.
Estradiol is the predominant form in nonpregnant females, estrone is produced during menopause, and estriol is the primary estrogen of pregnancy. In the body these are all produced from
androgens through actions of enzymes.
Estradiol is produced from testosterone.
A range of synthetic and natural substances have been identified that also possess estrogenic activity:
a) Synthetic substances of this kind are known as
xenoestrogens.
b) Plant products with estrogenic activity are called
phytoestrogens.
c) Those produced by fungi are known as
mycoestrogens.
Unlike estrogens produced by mammals, these substances are not necessarily steroids.
Estrogens are produced primarily by developing follicles in the ovaries, the corpus luteum, and the placenta.
Luteinizing hormone (LH) stimulates the production of estrogen in the ovaries. Some estrogens are also produced in smaller amounts by other tissues such as the liver, adrenal glands, and the breasts. These secondary sources of estrogens are especially important in postmenopausal women. Fat cells also produce estrogen, potentially being the reason why underweight or overweight are risk factors for infertility.
Estradiol levels vary through the menstrual cycle, with levels highest just before ovulation.
While estrogens are present in both men and women, they are usually present at significantly higher levels in women of reproductive age. They promote the development of female secondary sexual characteristics, such as breasts, and are also involved in the thickening of the endometrium and other aspects of regulating the menstrual cycle. Furthermore, there are several other structural changes induced by estrogen in addition to other functions [
link].
About 80% of breast cancers, once established, rely on supplies of the hormone estrogen to grow: they are known as hormone-sensitive or hormone-receptor-positive cancers. In 2009, a case-control study of the eating habits of 2,018 women, revealed that women who consumed
mushrooms had an approximately 50% lower incidence of breast cancer. Women who consumed mushrooms and
green tea had a 90% lower incidence of breast cancer.
[
missdelite:
How can mushrooms help prevent breast cancer when they contain mycoestrogens?]
In humans and mice, estrogen promotes wound healing.
The labeling of estrogen-only products in the U.S. includes a boxed warning that unopposed estrogen (without
progestagen) therapy increases the risk of endometrial cancer.
Some hair shampoos on the market include estrogens and placental extracts; others contain phytoestrogens. There are case reports of young children developing breasts after exposure to these shampoos. On September 9, 1993, the FDA determined that
not all topically-applied hormone-containing drug products for OTC (over-the-counter) human use are generally recognized as safe and effective and are misbranded. An accompanying proposed rule deals with
cosmetics, concluding that any use of natural estrogens in a cosmetic product makes the product an unapproved new drug and that any cosmetic using the term "hormone" in the text of its labeling or in its ingredient statement makes an implied drug claim, subjecting such a product to regulatory action.
In recent years it has been found that through waste water removal, estrogen has made its way into our ecosystems. Estrogen is among the wide range of endocrine-disrupting compounds (EDCs) due to the fact that they have high estrogenic potency. When this specific EDC makes its way into the environment it can cause severe male reproductive dysfunction to both humans and wildlife.
Breast - The breast is the upper ventral region of an animal’s torso, particularly that of mammals, including human beings. The breasts of a female primate’s body contain the
mammary glands, which secrete milk used to feed infants. Both men and women develop breasts from the same embryological tissues. However, at puberty, female sex hormones, mainly estrogen, promote breast development which does not occur in men. As a result, women's' breasts become far more prominent than those of men.
Anatomically, breasts are modified sweat glands. Each breast has one
nipple surrounded by the
areola. The color of the areola varies from pink to dark brown and has several
sebaceous glands. In women, the larger mammary glands within the breast produce the milk. They are distributed throughout the breast, with two-thirds of the tissue found within 30 mm of the base of the nipple.
About 75% of
lymph from the breast travels to the ipsilateral axillary
lymph nodes. The lymphatic drainage of the breasts is particularly relevant to oncology, since breast cancer is a common cancer and cancer cells can break away from a tumour and spread to other parts of the body through the lymph system by
metastasis.
As breasts are mostly composed of
adipose tissue, their size can change over time. This occurs for a number of reasons, most obviously when a girl grows during puberty and when a woman becomes pregnant. The breast size may also change if she gains (or loses) weight for any other reason.
In some cultures, breasts play an important part in human sexual behavior; they are also important female secondary sex characteristics. On sexual arousal breast size increases, venous patterns across the breasts become more visible, and nipples harden. Breasts are sensitive to touch as they have many nerve endings, and it is common to press or massage breasts with hands during sexual intercourse (as it is with other bodily areas representing feminine secondary sex characteristics as well). Oral stimulation of nipples and breasts is also common. Some women can achieve breast orgasms.
Factors that appear to be implicated in decreasing the risk of, or early diagnosis of breast cancer are regular breast examinations by health care professionals, regular mammograms, self examination of breasts, healthy diet, and exercise to decrease excess body fat. Healthy diet appears to reduce the risk of breast cancer, and includes limiting dietary fat, eating a balanced diet that includes plenty of nutrients, and dietary fibre such as are found in fruits and vegetables, and restricting intake of alcohol to a maximum of two drinks per day or less.
ALSO: Reproductive System /
Gland /
Progesterone /
Breast Cancer /
Hysterectomy /
G-Spot
