Female Anatomy

In order to have a complete understanding of the symptoms and conditions of female sexual dysfunction please use the following diagram and definitions to reference material presented in the website.

 


External Female Anatomy

Anus - the anus is where solid waste exits the body. The anus is surrounded by a group of sphincter muscles that allows individuals to control the solid waste being expelled from the body. While not connected to reproduction, the anus is still very highly sensitive to touch and can be a source of great pleasure.

Perineum - the perineum is the short stretch of skin starting at the bottom of the vulva and extending to the anus. This is the area in women often tears during birth to accommodate passage of the child, or is cut by the physician in a procedure know as an episiotomy to allow more room for the birth of the child. This region is highly sensitive and is often an area of pleasure during foreplay.

Labia Majora - the labia majora are the outer lips of the vulva, pads of fatty tissue that wrap around the vulva from top to bottom around the mons to the perineum. These labia are usually covered with pubic hair, and contain numerous sweat and oil glands.

Vagina - The vagina extends from the vaginal opening to the cervix, the opening to the uterus. The vagina serves as the receptacle for the penis during sexual intercourse, and as the birth canal through which the baby passes during labor. The average vaginal canal is three inches long, possibly four in women who have given birth. This may seem short in relation to the penis, but during sexual arousal the cervix will lift upwards and the fornix may extend upwards into the body as long as necessary to receive the penis. After intercourse, the contraction of the vagina will allow the cervix to rest inside the fornix, which in its relaxed state is a bowl-shaped fitting perfect for the pooling of semen.

Labia Minora - The labia minora are the inner lips of the vulva, the thin stretches of skin and tissue reside directly inside of the labia majora. The labia minora further protect the vagina, urethra, and clitoris. The overall appearance of labia minora can vary widely amongst women. Some women have small labia minora while others have larger lips that protrude from the labia majora. The labia minora is analogous to the male strotum.

Clitoral hood - this is the "hood" of flesh that partially or fully covers the un-stimulated clitoris. The hood serves to protect the sensitive clitoris below from unwanted stimuli.

Clitoris - this is the small light pink oval between the top of the labia minora and the clitoral hood. The clitorus is a small body of smooth spongy tissue that is highly sensitive contains some 8,000 nerve endings packed into one small area. Compare this with the penis, which only has some 4,000 nerve endings in a much larger area and you will have an understanding sensitive nature of the clitoral area.. The clitoris is protected by the prepuce, or clitoral hood, a covering of tissue similar to the labia minora. During sexual excitement the clitoris becomes erect and the hood retracts making the clitoris more accessible. The size of the clitoris various amongst women, they usually very from the size of a small green pea to the size of a peanut.

Mons veneris - is the area of fatty tissue that covers the pubic bone below the abdomen but above the labia. The mons is sexually sensitive in some women and protects the pubic bone from the impact of sexual intercourse. This is the region that contains the the familiar "triangle" of pubic hair just above the vulva.



Internal Female Anatomy 


Cervix - the cervix is the opening to the uterus. It varies in diameter from 1 to 3 millimeters, depending upon the time in the menstrual cycle the measurement is taken. The cervix is sometimes plugged with cervical mucous to protect the cervix from infection; during ovulation, this mucous becomes a thin fluid to permit the passage of sperm.

Uterus - the uterus, or womb, is the main female internal reproductive organ. The inner lining of the uterus is called the endometrium, which grows and changes during the menstrual cycle to prepare to receive a fertilized egg, and sheds a layer at the end of every menstrual cycle if fertilization does not happen. The uterus is lined with powerful muscles to push the child out during labor.

Fallopian tube - this is either of a pair of slender ducts through which ova pass from the ovaries to the uterus during the menstrual cycle.

G-spot - in the illustration above the g-spot points to a region just in the vagina adjacent to the bladder. The G-spot is a controversial area that many women claim is very sensitive and can lead to a heightened orgasm when stimulated during intercourse. Generally two fingers are used to stimulate this region during intercourse, however, the certain sexual positions have also been known to stimulate this spot.

Ovaries - the ovaries are 2 small glands located on either side of a woman's uterus. They are part of the female reproductive system that are responsible for storing and releasing of the eggs (ova), which can develop into fetuses if fertilized by a male's sperm. Approximately once a month, about 2 weeks before a woman's next period ovulation occurs were an egg is released from one of her ovaries The ovaries also produce female sex hormones (estrogen and progesterone), which help control the menstrual cycle, breast development, and other functions.

Fornix - this is the top inside of the vagina that extends slightly above and around the top and bottom of the cervix. During intercourse, the fornix balloons upwards in order to receive the penis. 

 


The Female Reproductive Cycle

Towards the end of puberty, girls begin to release eggs as part of a monthly period called the female reproductive cycle, or menstrual cycle (menstrual referring to "monthly"). Approximately every 28 days, during ovulation, an ovary sends a tiny egg into one of the fallopian tubes. Unless the egg is fertilized by a sperm while in the fallopian in the two to three days following ovulation, the egg dries up and leaves the body about two weeks later through the vagina. This process is called menstruation. Blood and tissues from the inner lining of the uterus (the endometrium) combine to form the menstrual flow, which generally lasts from four to seven days. The first period is called menarche. During menstruation arteries that supply the lining of the uterus constrict and capillaries weaken. Blood spilling from the damaged vessels detaches layers of the lining, not all at once but in random patches. Endometrium mucus and blood descending from the uterus, through the liquid creates the menstruation flow.

Menstrual cycle

The reproductive cycle can be divided into an ovarian cycle and a uterine cycle (compare ovarian histology and uterine histology in the diagram on the right). During the uterine cycle, the endometrial lining of the uterus builds up under the influence of increasing levels of estrogen (labeled as estradiol in the image). Follicles develop, and within a few days one matures into an ovum, or egg. The ovary then releases this egg, at the time of ovulation. After ovulation the uterine lining enters a secretory phase, or the ovarian cycle, in preparation for implantation, under the influence of progesterone. Progesterone is produced by the corpus luteum (the follicle after ovulation) and enriches the uterus with a thick lining of blood vessels and capillaries so that it can sustain the growing fetus. If fertilization and implantation occur, the embryo produces Human Chorionic Gonadotropin (HCG), which maintains the corpus luteum and causes it to continue producing progesterone until the placenta can take over production of progesterone. Hence, progesterone is "pro gestational" and maintains the uterine lining during all of pregnancy. If fertilization and implantation do not occur the corpus luteum degenerates into a corpus albicans, and progesterone levels fall. This fall in progesterone levels cause the endometrium lining to break down and sluff off through the vagina. This is called menstruation, which marks the low point for estrogen activity and is the starting point of a new cycle.

Common usage refers to menstruation and menses as a period. This bleeding serves as a sign that a woman has not become pregnant. However, this cannot be taken as certainty, as sometimes there is some bleeding in early pregnancy. During the reproductive years, failure to menstruate may provide the first indication to a woman that she may have become pregnant.

Menstruation forms a normal part of a natural cyclic process occurring in healthy women between puberty and the end of the reproductive years. The onset of menstruation, known asmenarche, occurs at an average age of 12, but is normal anywhere between 8 and 16. Factors such as heredity, diet, and overall health can accelerate or delay the onset of menarche.

Signs of ovulation

The female body produces outward signs that can be easily recognized at the time of ovulation. The two main signs are thinning of the cervical mucus and a slight change in body temperature.

Thinning of the Cervical Mucus

After menstruation and right before ovulation, a woman will experience an increase of cervical mucus. At first, it will be thick and yellowish in color and will not be very plentiful. Leading up to ovulation, it will become thinner and clearer. On or around the day of ovulation, the cervical mucus will be very thin, clear and stretchy. It can be compared to the consistency of egg whites. This appearance is known as 'spinnbarkeit'.

Temperature Change

A woman can also tell the time of ovulation by taking her basal body temperature daily. This is a temperature taken with a very sensitive thermometer first thing in the morning before the woman gets out of bed. The temperature is then tracked to show changes. In the uterine cycle, a normal temperature will be around 97.0 – 98.0. The day of ovulation the temperature spikes down, usually into the 96.0 – 97.0 range and then the next morning it will spike up to normal of around 98.6 and stay in that range until menstruation begins.

Both of these methods are used for conception and contraception. They are more efficient in conception due to the fact that sperm can live for two to three days inside of the fallopian tubes. A woman could be off by a couple of days in her calculations and still become pregnant.

Menopause is the physiological cessation of menstrual cycles associated with advancing age. Menopause is sometimes referred to as "the change of life" or climacteric. Menopause occurs as the ovaries stop producing estrogen, causing the reproductive system to gradually shut down. As the body adapts to the changing levels of natural hormones, vasomotor symptoms such as hot flashes and palpitations, psychological symptoms such as increased depression, anxiety, irritability, mood swings and lack of concentration, and atrophic symptoms such as vaginal dryness and urgency of urination appear. Together with these symptoms, the woman may also have increasingly scanty and erratic menstrual periods.

Technically, menopause refers to the cessation of menses; the gradual process through which this occurs, which typically takes a year but may last as little as six months or more than five years, is known as climacteric. A natural or physiological menopause is that which occurs as a part of a woman's normal aging process. However, menopause can be surgically induced by such procedures as hysterectomy.

The average onset of menopause is 50.5 years, but some women enter menopause at a younger age, especially if they have suffered from cancer or another serious illness and undergone chemotherapy. Premature menopause is defined as menopause occurring before the age of 40, and occurs in 1% of women. Other causes of premature menopause include autoimmune disorders, thyroid disease, and diabetes mellitus.

Premature menopause is diagnosed by measuring the levels of follicle stimulating hormone (FSH) and luteinizing hormone (LH). The levels of these hormones will be higher if menopause has occurred. Rates of premature menopause have been found to be significantly higher in both fraternal and identical twins; approximately 5% of twins reach menopause before the age of 40. The reasons for this are not completely understood. Post-menopausal women are at increased risk of osteoporosis.

Perimenopause refers to the time preceding menopause, during which the production of hormones such as estrogen and progesterone diminish and become more irregular. During this period fertility diminishes. Menopause is arbitrarily defined as a minimum of twelve months without menstruation. Perimenopause can begin as early as age 35, although it usually begins much later. It can last for a few months or for several years. The duration of perimenopause cannot be predicted in advance.

Premenstrual Syndrome (PMS) It is common for women to experience some discomfort in the days leading up to their periods. PMS usually is at its worst the seven days before a period starts and can continue through the end of the period. PMS includes both physical and emotional symptoms: acne, bloating, fatigue, backaches, sore breasts, headaches, constipation, diarrhea, food cravings, depression, irritability, difficulty concentrating or handling stress.


Ovarian and Uterine Cycles in the Nonpregnant Woman

An ovary about to release an egg.
Ovarian CycleEventsUterine CycleEvents
Follicular phase - Days 1-13FSH secretion begins.Menstruation - Days 2-5Endometrium breaks down.
Follicle maturation occurs.Proliferative phase - Days 6-13Endometrium rebuilds.
Estrogen secretion is prominent.
Ovulation - Day 14*LH spike occurs.
Luteal phase - Days 15-28LH secretion continues.Secretory phase - Days 15-28Endometrial thickens, and glands are secretory.
Corpus luteum forms.
Progesterone secretion is prominent.

(*)Assuming a 28 day cycle.

There are two phases of the ovarian cycle the follicular phase and the luteal phase. In the follicular phase about 10-25 follicles are taken from preantral or early antrial follicles to develop further. Seven days later the dominant follicle is selected to develop to full maturity. This is the pre-cursor for ovulation. Follicles themselves secrete FSH and estrogen, and these two hormones stimulate follicular growth and development. Ovulation marks the beginning of the luteal phase. This is started by the wall of the Graffian follicle to rupture and cause a flow of antral fluid that will carry the oocyte to the ovary's surface. The ruptured follicle is then turned into a gland (corpus luteum). Which secretes estrogens and progesterone. This is all triggered by and abrupt change in plasma LH levels. After ovulation the released oocyte enters the uterine tube, where it will be either fertilized or discarded.

The uterine cycle operates in sync with the ovarian cycle and is divided into three phases. The first phase in the menstrual phase. It is named the menstrual phase because in corresponds with the shedding the the uterine lining or more commonly called menstruation. The corpus luteum degenerates causing plasma estrogen and progesterone levels to decrease and in turn causes menstruation. Blood vessels in the outer most layer of the endometrium constrict and decrease blood flow to the tissues killing these tissues. After the tissues die they start to separate from the underlying endometrail tissues. Eventually the dead tissue is shed. This shedding of the tissues ruptures blood vessels and causes bleeding. Now we have the proliferative phase. During this phase the uterus renews itself and prepares for pregnancy. The endomitrial tissue that is left after menstruation begins to grow. The endometrial glands grow and enlarge causing more blood vessels. The cervical canal has glands that secrete a thin mucous that helps deposited sperm. Estrogen promotes uterine changes in this phase. The last phase is the secretory phase. This is where the endometrium is transformed to make it the best environment for implantation and subsequent housing and nourishment of the developing embryo. By doing this the endometrium will do things like have an enriched blood supply, begin to secrete fluids rich in glycogen, and even form a plug at the end of the cervical canal so that microorganisms can not enter. These changes in the uterus are caused by progesterone, due to the corpus luteum. At the end of the secretory phase the corpus luteum degenerates, and progesterone levels fall. This will trigger menstruation.


Sexual Reproduction

Sexual reproduction is a type of reproduction that results in increasing genetic diversity of the offspring. In sexual reproduction, genes from two individuals are combined in random ways with each new generation. Sex hormones released into the body by the endocrine system signal the body when it is time to start puberty. The female and male reproductive systems are the only systems so vastly different that each sex has their own different organs. All other systems have "unisex" organs.

Reproduction is characterized by two processes. The first, meiosis, involves the halving of the 46 of chromosomes. The second process, fertilization, leads the fusion of two gametes and the restoration of the original number of chromosomes: 23 chromosomes from the paternal side and 23 from the maternal side. During meiosis, the chromosomes of each pair usually cross over to achieve genetic recombination.

Sexual reproduction cannot happen without the sexual organs called gonads. Both sexes have gonads: in females, the gonads are the ovaries. The female gonads produce female gametes (eggs); the male gonads produce male gametes (sperm). After an egg is fertilized by the sperm, the fertilized egg is called the zygote.

The fertilization usually occurs in the oviducts, but can happen in the uterus itself. The zygote then implants itself in the wall of the uterus, where it begins the processes of embryogenesis and morphogenesis. The womens body carries out this process of reproduction for 40 weeks, until delivery of the fetus from the uterus through the vagina (birth canal). Even after birth, the female continues with the reproduction process by supplying the milk to nourish the infant.



( Data and pictures have been taken and modified from other websites like 
www.wikipedia.org )

 
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