The Reproductive System
5.2a The physiology of the reproductive system9
The function of the reproductive system in both sexes is to ensure the reproduction of the human species. To do this, first, the reproductive system of each sex has to be able to produce healthy sex cells or gametes. These are the ova (singular ovum) from the female, and the spermatozoa (sperm) from the male. A second function of the reproductive system of each sex is to enable the meeting of these gametes to enable fertilization following the act of sexual intercourse.
The gametes originate from specialized cells called germ cells, which are formed within the ovaries in females and the testes in males. The gametes are the result of the particular form of cell division known as meiosis.
It is the role of the female reproductive system to provide a suitable environment for the implantation and nourishment of the fertilized egg, known as the zygote. This role continues for the 40 weeks of pregnancy, as the zygote divides and enlarges through the stages of embryo and fetus in the womb. The female reproductive tract then has to ensure the safe expulsion of the fetus during labor. Finally, it has to undergo all the changes of the postnatal period, which allow the woman to return, as much as possible, to her pre-pregnant state.
This chapter focuses on the male reproductive system and the non-pregnant female reproductive system. The study of the male reproductive system is conventionally termed andrology, and the study of the non-pregnant female reproductive system is termed gynecology (derived from the Greek words for man and woman, respectively). Chapter 5.3 is then dedicated to the conditions of pregnancy, labor and the postnatal period. The study of these conditions is conventionally referred to as obstetrics. This section considers the physiology of the male and female reproductive system in turn, and concludes with a brief discussion about the physiology of sexual intercourse.
The physiology of the male reproductive system
The male reproductive system consists of the testes, epididymis, urethra, penis and associated glands, including the prostate gland. Figure 5.2a-I illustrates the anatomy of this system and Figure 5.2a-II shows the structure of the testis and scrotum in more detail.
The testes are the paired male sex glands, or gonads, and sit suspended from the perineum within the sacs formed by the scrotum. The two main products of the testes are spermatozoa (originating from the germ cells of the seminiferous tubules) and the male sex hormone testosterone (originating from the interstitial cells of Leydig).
The pituitary gland produces follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which play an important role in the function of the testes. FSH stimulates the production of spermatozoa from the germ cells. LH stimulates the production of testosterone from the testes. The levels of both these hormones surge at puberty.
Figure 5.2a-I The anatomy of the male reproductive system
a) Interior of erect penis. b) Lateral view of male genitalia and bladder
Figure 5.2a-II The anatomy of the testis and the scrotum
A mature sperm cell has a head, a body and a motile tail, which propels the sperm cell forwards by means of a whip-like motion. The formation of sperm is most efficient at about 3°C below body temperature, which is aided by the fact that the testes sit in the scrotum. Spermatozoa are secreted from the germinal cells of the testis into the epididymis. The epididymis is a complex of very fine tubules, which store and direct spermatozoa towards the vas deferens. Testosterone is secreted from the cells of Leydig directly into the bloodstream. Thus the testis is, strictly speaking, both an exocrine and an endocrine gland.
The spermatic cords emerge from a gap in the musculature above the inguinal ligament and provide the testes with a blood and nerve supply. They also contain the vas deferens. The purpose of the vas deferens is to carry the spermatozoa away from the testes and the epididymis, and to lead towards the urethra, from which the spermatozoa can be ejaculated. It is this tube that is severed and tied off in the procedure of vasectomy.
The prostate gland and seminal vesicles are exocrine glands that produce nutrient-rich lubricating fluid to maximize the survival of the spermatozoa and also to promote comfortable sexual intercourse. The seminal vesicles each open out into the distal portion of the two vas deferens, and the prostate gland is situated at the base of the bladder at the point at which the vas deferens ducts enter the urethra. The prostate hugs the most proximal region of the urethra, which is why this portion is described as the prostatic urethra. The fluids produced by these glands mix with the spermatozoa in the urethra during ejaculation to form semen.
The onset of puberty in the boy
The pituitary gland responds to hormonal changes in the maturing hypothalamus to trigger the changes of puberty in both boys and girls. In both, puberty is preceded by a surge of growth hormone (GH) from the pituitary gland, and this becomes manifest as a pre-pubertal growth spurt. Then, in both, the pituitary starts to produce increasing quantities of LH. In boys, this stimulates the interstitial cells of the testes to produce testosterone, and it is testosterone that influences the tissues of the body to change and allows the secondary sexual characteristics to emerge.
•enlargement of the testicles, penis and scrotum
•pubic hair growth in the groin and axilla
•increased facial and body hair, and thickening of the skin
•enlargement of the vocal cords and breaking of the voice
•increased muscle mass and bone density.
The male reproductive system: comments from a Chinese medicine perspective
In Chinese medicine, the male reproductive system is dominated by the Kidney and Liver Organs. Healthy Qi and Kidney Essence (Jing) are key substances essential for male reproductive health.
The Kidney and Liver Channels pass across the anatomical location of the male genitalia. In sexes, sexual maturation and fertility is underpinned by Jing, which is recognized to flow in eight-year cycles in men. Healthy Qi enables a healthy sexual response.
The Kidney Organ is said to control the two lower orifices. This is reflected in the fact that impotence and inappropriate seminal emissions are features of Deficiency of both Kidney Yang (including Kidney Qi not firm) and Kidney Yin. In contrast, the Liver Organ appears to have more bearing on the external genitalia. Damp Heat in the Liver can manifest as soreness or itchiness of the scrotum, whereas Cold in the Liver Channel can give rise to deep pain in the scrotum.
The physiology of the female reproductive system
The female reproductive system lies at a deeper level in the body than in the male (see Figures 5.2a-III and 5.2a-IV). The ovaries sit deep in the basin formed by the pelvis, and lay either side of the womb (uterus). The ovaries are positioned close to the openings of two tubes (the fallopian tubes) that extend sideways from the uterus. The uterus is a pear-sized organ sitting just behind and above the bladder, protected in front by the bridge formed by the pubic bone. The neck of the uterus (the cervix) opens into the bodily space called the vagina. The entrance of the vagina, the vulva, is surrounded by the fleshy lips of the labia minora and labia majora in the perineum.
Figure 5.2a-III The uterus and ovaries in the pelvis (anterior view)
Figure 5.2a-IV The female reproductive system in the pelvis (lateral view)
The system in more detail
The vagina is a tube-like space with tough muscular walls. It is approximately 8cm long. The interior of the vagina is kept moist by secretions that originate from tiny glands in the cervix. The lining of the vagina is colonized by healthy bacteria called Lactobacillus acidophilus. These secrete an acid called lactic acid, and so keep the interior of the vagina slightly acidic. Lactobacilli are the same type of bacteria that are used to turn milk into live yoghurt. The acidic environment created by the Lactobacillus helps keep the growth of less desirable bacteria and yeasts at bay.
In young girls, the opening of the vagina is partially closed by means of a thin sheet of tissue called the hymen. A small opening in the hymen permits the escape of menstrual blood at the onset of puberty. The hymen is always stretched during first intercourse. Tearing of the hymen with a small amount of bleeding can happen at first intercourse, or may occur earlier in an active teenager. The finding of a torn hymen in a prepubescent child is not normal, and is an indicator of possible sexual abuse.
The uterus is a hollow organ with three narrow openings formed by the cervix and the two fallopian tubes. The wall of the uterus is composed of a thick layer of smooth muscle called the myometrium. The lining of the uterus is called the endometrium. This is composed of columnar epithelium and contains a large number of mucus-secreting glands. The thickness of this layer varies throughout the monthly menstrual cycle.
The endometrium extends to the lower third of the narrow entrance to the cervix, which is known as the cervical canal. Below this there is a transition to squamous epithelium, which lines the vagina.
THE FALLOPIAN TUBES
The fallopian tubes receive the ovum from the ovary and aid its transport towards the space within the body of the uterus. To do this, the fallopian tubes have frond-like projections at their distal ends. These fronds and also the interior of the fallopian tube are lined with ciliated epithelial cells. When the ovum is released, ciliary movement wafts the ovum into and through the tube. The fallopian tube is the usual location for the fertilization of the ovum and the spermatozoon. The fertilized zygote is then transported into the endometrium in preparation for implantation by means of the ciliary movement of the lining of the fallopian tubes.
The ovary is the female sex gland or gonad. The ovary originates from exactly the same embryonic tissue as the testis. During development of the male fetus, this embryonic tissue, originally positioned in the abdomen, develops into the testis and migrates into the scrotum under the influence of male sex hormones. In the female fetus, in the absence of these male hormones, the tissue remains where it is and develops into the ovary.
The ovary is the site for the maturation of the ova, and this takes place during the course of the first half of the menstrual cycle, during which usually only a single ovarian follicle enlarges. Ovarian follicles each consist of a single ovum and are lined by ovarian cells. By the time the female baby is born, her ovaries contain all the ova, each within its own ovarian follicle, which will be released during her childbearing years.
During the first half of the menstrual cycle, a single ovarian follicle begins the process of maturation (see Figure 5.2a-V). This involves the follicle enlarging and developing a fluid-filled cavity over the course of approximately 14 days. This so-called mature Graafian follicle then merges with the outer part of the ovary and ruptures to release the single ovum into the space surrounding the ovary. This process of rupture and release is what is termed ovulation. The whole process is stimulated first by FSH from the pituitary gland, and this explains its name. FSH is the same hormone that in men stimulates the development of spermatozoa from germinal cells.
During the first 14 days of the menstrual cycle, the multiplying follicle cells secrete the female sex hormone estrogen, also under the influence of FSH. The rising estrogen levels have a suppressive (negative feedback) effect on the secretion of FSH. As the FSH levels start to drop, the pituitary then releases a surge of a second hormone, LH. It is this hormone that stimulates ovulation. After ovulation, the remaining follicle develops into a body known as the corpus luteum (the origin of the term luteinizing hormone). Under the influence of LH the corpus luteum no longer produces estrogen, and instead releases the other female sex hormone, progesterone.
The corpus luteum matures and then degenerates over the course of the next 14 days. As the corpus luteum degenerates, it ceases to produce progesterone. However, if fertilization occurs, this degeneration does not happen, and instead the corpus luteum continues to develop. This is a result of the multiplying cells of the zygote that secrete the hormone human chorionic gonadotropin (HCG). This stimulates the corpus luteum and prevents its degeneration. Thus, in early pregnancy the progesterone levels continue to rise.
To summarize, after puberty, the ovarian follicle is the source of a cyclical release of the female sex hormones. Estrogen is released in the first half of the menstrual cycle, and progesterone in the second half of the menstrual cycle. This cycle is controlled by the cyclical release of the pituitary hormones FSH and LH.
As is the case for boys, in girls the onset of puberty is also stimulated by a rise in the production of FSH and LH. This usually occurs between the ages of 10 and 14.
Two to three years prior to this surge in FSH and LH in both boys and girls there is an increase in the release of GH from the pituitary gland. The release of GH stimulates the growth spurt that occurs in children just before puberty. In girls, the rise in FSH and LH stimulates the production of increasing amounts of estrogen from the follicle cells of the ovaries. Initially, these pituitary hormones are not present in sufficient quantities to stimulate ovulation. However, the estrogen produced affects diverse body tissues to bring about the early changes of puberty, including breast development and the growth of pubic hair. As puberty approaches, the levels of FSH and LH increase until ovulation is stimulated.
At approximately the same time as the onset of ovulation, menstruation begins. The onset of menstruation is termed the menarche. It is recognized that ovulation may occur for a few cycles before the first menstrual bleed. This means that there is a possibility of pregnancy even before menstruation has started.
The onset of puberty in both girls and boys in Westernized cultures is occurring at an increasingly early age. The average age of onset of menstruation is four years earlier now than it was a century ago.10 This suggests that it is not purely biological programming that stimulates the dramatic increase in the release of FSH and LH that initiates puberty. It is now believed that both nutritional and psychological factors also play a part in this hormonal change. These are believed to influence the physiology of the pituitary via the production of specific hormones from the hypothalamus.
A child who is less well nourished is more likely to experience a delayed onset of puberty. Conversely, a child who achieves a degree of psychological maturity, particularly with regard to understanding or experience of sexual matters, appears to experience an earlier onset of puberty. Both these factors tend to promote the earlier onset of puberty in girls who grow up in modern cultures.
The changes that take place in the ovary after the onset of ovulation have a cycle of approximately 28 days, although any interval between 22 and 35 days is considered conventionally to be within the normal range. These changes are mirrored by cyclical changes in the uterus and vagina as well as many other tissues in the body. They are the result of the rise of estrogen in the first half of the cycle and in progesterone in the second half of the cycle.
Estrogen can be considered as a hormone that stimulates fleshiness. In the first half of the cycle, it continues to promote the healthy development of the breasts and pubic hair. It also stimulates and maintains the changes to the skin, body fat and bony skeleton (in particular, the hips and pelvis) that are characteristic of the female body. In the uterus, it stimulates a thickening of the endometrium, with the development of deep mucus-forming glands and a rich supply of blood vessels. About three days before ovulation thick sticky mucus is secreted from the cervix. This mucus encourages the passage of spermatozoa at the time when the woman is likely to be most fertile. This phase of the menstrual cycle is termed the proliferative phase, a term that refers to the changes taking place in the endometrium at that time.
Estrogen promotes fleshiness of the tissues of the vagina and the labia majora and minor. It also promotes the vaginal secretions that are particularly important for comfortable sexual intercourse.
Progesterone can be considered to be the hormone that prepares the body for pregnancy and promotes the first three months of pregnancy. After ovulation, the rising levels of progesterone stimulate a watery swelling of the endometrium and the production of thick mucus. This mucus is believed to encourage the passage of the spermatozoa into the fallopian tubes, where fertilization can take place. The changes in the endometrium provide a suitable environment for the zygote. If implantation does not occur, at about 6–8 days after ovulation, the corpus luteum starts to degenerate, and progesterone levels drop. It is this drop that causes the lining of the endometrium to start to break down, culminating in menstruation at 14 days after ovulation. There are thus two distinct phases to this second half of the menstrual cycle, termed the secretory phase and the premenstrual phase (see Figure 5.2a-VI).
Figure 5.2a-VI Diagrammatic summary of one female menstrual cycle
Normal menstruation takes place over the course of three to seven days. As blood, endometrial lining cells and tissue fluid are shed, chemicals are released that stimulate the muscle wall of the uterus to contract, so that bleeding is minimized, and the products are effectively cleared from the uterus. This contraction is the cause of the cramping pain of menstruation. A degree of pain is therefore considered to be normal from a conventional perspective. It is helpful to understand that menstrual blood is not pure blood. A heavy period may not necessarily indicate a large loss of blood cells, as much of the volume of what is lost may be tissue fluid.
While menstruation is occurring, the release of FSH initiates the next cycle, with the stimulation of the maturation of another ovarian follicle. This is why the first day of the menstrual bleed is conventionally considered to be the first day of the whole menstrual cycle.
The menopause is the term commonly used to describe the time in life, usually between the ages of 45 and 55, when menstruation ceases. Strictly speaking, the conventional use of the term menopause is to describe the precise time of cessation of menstruation. The term climacteric is used to describe the period of approximately ten years that precedes and follows this event.11
The aging ovaries are the cause of the onset of the climacteric. Gradually, the ovaries become less and less responsive to the pituitary hormones. This means that more and more of the menstrual cycles fail to lead to ovulation, and the production of estrogen drops. The rate of drop in estrogen levels varies widely between women, and this might explain why some women experience more profound symptoms than others during the climacteric.
Other features of a lack of estrogen include a reduction in the strength of the pelvic floor muscles, with increased risk of prolapse of the vagina and uterus. Urinary problems, including urinary infections and stress incontinence, can occur because of a combination of reduced pelvic floor tone and changes in the lining of the skin around the opening of the urethra.
The notorious hot flashes are a consequence of a rapid drop in estrogen levels. The symptoms of these include bouts of profuse sweating and heat intolerance, often occurring at night. These can be accompanied by a range of bodily and psychological symptoms, which are not conventionally considered to be necessarily related to a lack of estrogen.
A lack of estrogen also promotes loss of calcium from the bones. This can occur very rapidly during the climacteric and can result in the symptoms of osteoporosis.
As the ovaries become less responsive to the control of the pituitary hormones, menstrual cycles become increasingly irregular. Some women experience increased frequency of menstruation, sometimes with excessive bleeding, for months to years, before the menopause. Usually just before the menopause the periods become lighter and more infrequent.
As the climacteric approaches, women become increasingly infertile as fewer and fewer cycles lead to ovulation. However, onset of the menopause does not necessarily mean that ovulation has ceased. In some women ovulation may still occur for a short time. This explains why it is that, in very rare circumstances, pregnancy can still happen after a woman’s periods have ceased. Women who reach the menopause before the age of 50 are counseled to continue to use contraception for two years after the menopause, and those over 50 are advised to continue using contraception for one year.
The breasts develop in the female under the influence of progesterone and estrogen during puberty. Each breast contains a lot of fatty tissue in which numerous exocrine glands, called lobules, are embedded. The lobules are responsible for milk production. During lactation milk is secreted from the lobules into ducts called lactiferous ducts. Before these open out into the nipple, each duct widens into a reservoir for milk called a sinus. The health of both the lobules and this fatty tissue is maintained up until the time of the menopause by estrogen released by the maturing ovarian follicles.
The breast is prepared for milk production during pregnancy by the influence of estrogen and progesterone. Milk production is stimulated by two pituitary hormones: prolactin (PRL) stimulates the formation of milk in the lobules, and oxytocin stimulates the contraction of the ducts and sinuses, which leads to the letdown of milk towards the nipple. Suckling is one stimulus for the release of these two hormones.
The female reproductive system: comments from a Chinese medicine perspective
From a Chinese medicine perspective, the physiology of the female reproductive system is complex. The extra Yang Organ, the Uterus, is the central organ, but the Spleen, Stomach, Liver, Heart and Kidneys all have important roles. The four Extraordinary Vessels, the Ren Mai, Du Mai, Chong Mai and Dai Mai, are important regulatory Channels. Additional Channels, the Bao Mai and Bao Luo, which link the Uterus with the Heart and the Kidneys, respectively, are also important for the regulation of the female reproductive system.
Blood and Kidney Essence (Jing) are the important substances for a healthy female reproductive system. It is Heart Blood that fills and nourishes the Uterus, and so the Spleen and the Liver Organs are responsible for the manufacture and the smooth movement of this Blood. However, Jing is required in addition to Heart Blood for menstruation to occur, as it is the basis of the menstrual blood. In women, Jing is believed to flow in seven-year cycles. The Spleen and Jing may be the foundation of the action of estrogen, as together they give rise to fleshy characteristics, fertility and strong bones.
The deep origin of all three of the Extraordinary Vessels (Ren Mai, Du Mai and Chong Mai) is the region of the Kidneys. These then all flow through the energetic region described in Chinese medicine as the Uterus before reaching their more superficial pathways.
The Chong Mai, as the Sea of Blood, has a strong influence on menstruation. The Chong Mai is linked to the Stomach Channel via ST-30 (Qi Chong). This explains how nausea can be a problem in conditions such as dysmenorrhea and morning sickness.
The Ren Mai governs the cervix, vagina and the vulva. It also helps to provide the other Yin substances important in female reproductive physiology (Yin, Essence and Fluids), as it is the Sea of the Yin Channels. It is therefore important in the regulation of fertility, puberty, pregnancy and the menopause.
Because of its complex pathway, the Du Mai also influences the vagina and the vulva. The Du Mai together and the Ren Mai together can be seen as two branches of one circuit that interlinks the Uterus with the other Organs. The Dai Mai encircles the waist, and so crosses the leg channels. In this way it influences the smooth flow of Qi in the Liver Channel and harmonizes the Kidneys and the Spleen.
The relative strength of the organs and substances in the four menstrual phases correspond to the physiological phases understood in conventional terms. These are (with conventional terms in parentheses):
•Menstruation: Blood is moving, and is reliant on smooth Liver Qi and Liver Blood.
•Postmenstrual (proliferative phase): Blood and Yin are Empty and Chong Mai and Ren Mai are Empty.
•Mid-cycle (secretory phase): Blood and Yin fill up in Chong Mai and Ren Mai.
•Premenstrual (premenstrual phase): Yang Qi Rises and Liver Qi Moves. This phase does not occur if implantation takes place.
At the climacteric, there is a decline in the Kidney Essence and in the Qi and Blood of the Ren Mai and Chong Mai. There is thus a general drying up of body fluids (Yin Deficiency). This culminates in the cessation of menstruation.
The physiology of sexual intercourse
Sexual intercourse is necessary for natural conception to occur. It enables the meeting of the spermatozoa and the ovum in the fallopian tubes. It is, of course, also a very important aspect of bonding in human relationships.
Despite the overt differences, the physiological processes that take place during sexual intercourse are very similar in men and women. The sexual act, for both men and women, has been described as taking place in five phases, although these phases tend to merge into one another. These phases are:
•Sexual desire: the emotional/mental response to the thought, sight, touch or smell of another person.
•Sexual arousal: following sexual desire, physical changes take place in the sex organs (genitalia). The penis and clitoris become erect and the vagina becomes lubricated. The nipples can become erect. The heart rate can increase. There is a strong desire for sexual intercourse. This phase is mediated by the parasympathetic aspect of the nervous system.
•Plateau: sexual pleasure is intensified and sustained before and after penile penetration has taken place. This phase is also mediated by the parasympathetic nervous system.
•Orgasm: orgasm usually results in ejaculation of semen in men. In penile/vaginal intercourse, the semen is directed deep into the vagina, close to the entrance of the cervical canal. Ninety percent of women are able to achieve orgasm, although only 25 percent will be able to reach orgasm through penile penetration into the vagina alone. There are rhythmic contractions of the perineal muscles of the women at orgasm. These contractions encourage the upward movement of the semen towards the cervix. The orgasmic phase is mediated by the sympathetic aspect of the nervous system.
•Resolution: after orgasm, both partners are relaxed, and the body gradually returns to a non-aroused state. In this phase the parasympathetic nervous system is dominant. The resolution state encourages rest, and for the woman this is the ideal state for the continued passage of the spermatozoa into the cervical canal and thence into the uterus.
5.2b The investigation of the reproductive system
The investigation of the female reproductive system is usually carried out within the hospital specialty of obstetrics and gynecology. The hospital specialist who deals with the all the disorders of the non-pregnant female reproductive tract is called a gynecologist. However, breast disorders are, in general, managed by a general or a specialist breast surgeon.
Disorders of the male reproductive system are often investigated within the surgical specialty of urology. In some hospitals there may be a dedicated andrology unit.
Sexually transmitted diseases are usually managed within the hospital specialty of genitourinary medicine (GUM). In the UK, in contrast to all other hospital specialties apart from accident and emergency medicine, patients can self-refer to a GUM department. The content of each consultation is kept strictly confidential and is not even revealed to the patient’s general practitioner (GP).
The investigation of the female reproductive system
The investigation of the female reproductive system includes:
•a thorough physical examination, including internal examination of the uterus and ovaries
•blood tests and urine tests to assess hormone levels
•examination of samples of vaginal mucus
•cervical cytological examination (Pap smear)
•imaging tests (in particular, pelvic ultrasound, endoscopy of the vagina and the womb, laparoscopy and hysterosalpingography) to visualize the structure of the reproductive organs
•biopsy of the endometrium.
Gynecological physical examination
The main part of the gynecological examination is the internal pelvic examination. For this examination the woman has to lie on her back, with knees bent and feet apart. In the first part of the examination the doctor inserts two gloved fingers of the right hand into the vagina, whilst palpating the suprapubic area of the abdomen with the left. In this bimanual examination the shape of the cervix can be assessed, and structural problems of the uterus and the ovaries may be detected. The doctor then inserts an instrument made of metal or plastic called a speculum into the vagina. The speculum parts the soft tissue of the vaginal walls, and allows the doctor to see the cervix. A speculum is necessary to perform a cervical cytological examination (Pap smear) test.
If the patient can relax, these tests should not be painful. However, many patients find these procedures undignified or embarrassing. They can be very traumatic for those with a past history of sexual difficulties or abuse. The muscle tension that results from resistance to the idea of these tests can make insertion of the examining fingers or the speculum much more difficult, and potentially painful.
Blood and urine tests
Blood tests may be taken to examine the levels of FSH, LH and the sex hormones. As all these hormones vary dramatically throughout the menstrual cycle, it is important to record the time of day and the day of the cycle on which the test is taken.
Urine may also be examined for hormone levels. The most commonly performed urine test is the pregnancy test. This looks for the rising levels of HCG that appear shortly after implantation of the fertilized ovum (zygote).
Examination of vaginal mucus
A sample of vaginal mucus can be obtained by means of a swab inserted during a speculum examination. This test may be performed to investigate possible infectious disease, in which case the swab is sent to a laboratory to look for evidence of microorganisms.
Alternatively, the mucus may be examined as part of natural family planning and also in the investigation of infertility. The patient can be taught to examine her own mucus, and to look for the characteristic changes in consistency that occur at ovulation. When the mucus is at its most profuse and sticky, ovulation is occurring and fertility is at its peak.
The postcoital test is a test of the cervical mucus taken within eight hours of intercourse and is timed to occur in the two days leading up to ovulation. In this test the mucus should contain sperm. The test is to examine whether or not the sperm are able to penetrate the mucus in a normal way. If they cannot, this may suggest a condition in which the mucus contains antibodies that are specific to the antigens on the sperm, and which prevent the sperm from penetrating the cervical opening.
Cervical cytological screening (formerly known as the Pap smear test)
The cervical screening test is designed to examine for early precancerous changes to the cervical cells. The aim is to detect such changes at a time when they can be simply treated by local laser treatment or excision.
In the cervical screening test, the opening to the cervix is visualized by means of a speculum. The cervix is then swept gently with a brush to obtain a sample of the mucus. This process should be painless. The end of the brush is then stirred into a fluid designed to maintain living cervical cells. The sample of cell transport fluid is then sent to a cytology laboratory for microscopic examination. The examination looks for abnormally shaped (dysplastic) cervical cells, which may be an indication of early cancer. It is also possible to test for the very common wart virus (human papilloma virus, HPV) infection as part of the examination. This is now widely performed to offer more prognostic information. The cervical screening test is offered to all women in the UK between the ages of 25 and 65 at regular (three-yearly and then five-yearly) intervals as part of a national screening program.
Cervical screening is not wholly reliable, in that many women who have no physical abnormality will have unclear smear test results and will have to be recalled for re-examination (false-positive results), and some cervical cancers will be missed (false-negative results). Many women are recalled for the more invasive colposcopy treatments on the basis of slight abnormalities that may never have developed into cancer.
There is ongoing debate over whether the cost of the program and its inconvenience to many women is outweighed by the advantages of the early detection of cancer in a few. However, it has been estimated that the UK cervical screening program saves about 3000 lives per annum by preventing the development of advanced cervical cancer. There was a 43 percent reduction in cervical cancer incidence from 1987 to 1997 in the UK that followed the introduction of the screening program.
The introduction of HPV vaccination in teenage girls is likely to impact positively on the incidence of cervical cancer in the long term. It may be possible that the rates of this cancer may drop to such an extent that there will no longer be a need for the screening program.12
Imaging tests and biopsy
Because the uterus and ovaries are deep organs, imaging tests are very often necessary to provide more information.
The pelvic ultrasound scan is a non-invasive examination that can provide very useful information. The test usually involves the use of a vaginally inserted probe so that the uterus can be examined from within the bowl of the pelvis. Tumors and cysts of the ovaries and uterus can be visualized by means of an ultrasound examination. The formation of the Graafian follicle can be seen, and so ultrasound can give an indication of healthy ovulation.
Endoscopy of the vagina (colposcopy) is a test that requires the insertion of a vaginal speculum. A colposcope (a form of endoscope) is used to provide detailed images of the surface of the cervix, and permits the removal of cervical biopsies and treatment of the cervix. This investigation is most commonly used to provide more information and treatment after an abnormal cervical cytology test.
Endoscopy of the uterus (hysteroscopy) requires the insertion of a fine endoscope into the uterus via the cervical canal. This is usually performed in an outpatient setting in a conscious patient. The test can be uncomfortable, as the cervix is very sensitive. Hysteroscopy is used in the investigation of menstrual disorders, and is the means by which samples of the endometrium may be obtained for microscopic examination.
Laparoscopy is a procedure in which a fine endoscope is inserted into the peritoneal cavity that surrounds the pelvic organs. The endoscope is inserted via a small incision made adjacent to the umbilicus. Laparoscopy can reveal the details of the external anatomy of the ovaries and the uterus. It can visualize ovarian cysts and the changes that occur in endometriosis. Laparoscopy is also the means by which some important gynecological procedures can be performed. These include sterilization, removal of ovarian cysts and removal of eggs for assisted-fertilization techniques.
Hysterosalpingography (HSG) is a test to examine the interior anatomy of the fallopian tubes. A dye that is opaque to X-rays is injected into the cervical canal, and X-ray images taken of the pelvic area. The dye can reveal the interior shape of the uterus and fallopian tubes, and thereby whether or not the fallopian tubes are blocked.
Endometrial biopsy is performed by means of hysteroscopy. A sample of the lining of the womb is removed from a conscious patient by means of a spoon-shaped instrument called a curette. The patient is likely to experience cramping pain and some bleeding after this procedure.
A less invasive method of obtaining endometrial samples is by means of a fine-ended suction instrument called a Pipelle curette. This samples far less endometrium but still has a greater than 90 percent detection rate for endometrial cancer.
The investigation of breast diseases includes:
•physical examination of the breasts and armpits
•withdrawal of fluid from cysts and biopsy
Physical examination of the breasts and armpits
Physical examination of the breasts involves observation for lumps or asymmetry, and systematic palpation for lumps. The examination should extend into the axilla (the armpit), into which the breast tissue extends. The axillary lymph nodes are also examined.
Women should be encouraged to perform this examination on themselves on a regular basis. The techniques of breast self-examination can be learned from a GP or practice nurse.
Fluid drainage and biopsy
Some lumps in the breast are cysts that contain fluid. This fluid can be withdrawn by means of a fine needle and syringe, and then examined under a microscope. A wider needle and syringe may be used to obtain a sample of the cells in a lump. Alternatively, a minor operation might be required to remove a small sample of tissue for a biopsy.
An ultrasound scan is commonly used in the investigation of breast lumps in outpatients. The scan can clearly demonstrate the fluid within breast cysts, and also indicate any irregular areas of growth, which may be suggestive of breast cancer.
Mammography is the term given to describe X-ray examination of the breasts. This test is offered to women in the UK aged 50–70 at one- to three-year intervals as part of the National Health Service (NHS) breast screening program.
Mammography is given with the intention of detecting breast cancer in an early (operable) stage. Like the cervical smear test, it is not a wholly reliable test, in that many women who have normal results will have to be recalled for re-examination (false-positives), and some breast cancers will be missed (false-negatives). Also, as for the cervical smear test, there is ongoing debate over whether the cost of the program and its inconvenience to many women are outweighed by the advantages of the early detection of cancer in a few.
The investigation of the male reproductive system
The investigation of the male reproductive system includes:
•a thorough physical examination, including examination of the testes and penis
•blood tests to assess hormone levels and to look for tumor markers
•visualization of the testes and prostate
Physical examination of the male reproductive system
The examination of the male reproductive system involves inspection and visualization of the male genitalia and palpation of the scrotum. Palpation will reveal the shape and consistency of the testes, and also the spermatic cords and the epididymis. The inguinal (groin) lymph nodes are also examined. Men should be encouraged to examine their own testes on a regular basis. The techniques of testicular self-examination can be learned from a GP or practice nurse.
The prostate is examined by means of digital rectal examination (i.e. the physician inserts a gloved finger into the anus).
Blood tests can be used to assess levels of FSH, LH and the sex hormones, although these tests are much more commonly performed in women than in men.
Testicular cancer and prostate cancers can secrete characteristic chemicals known as tumor markers, such as prostate-specific antigen (PSA). Blood tests may be taken for tumor markers in the diagnostic stages of cancer, but also during treatment to assess progress.
A fresh sample of semen that has been obtained by masturbation can be submitted to a range of tests to assess fertility. The volume and consistency of the semen, the number (sperm count) and the shape and movement of the spermatozoa can be analyzed and compared to the normal ranges.
Visualization of the testes and prostate
The structure of the testes and prostate may be examined in more detail by means of an ultrasound scan. The examination of the prostate requires the insertion of an ultrasound probe into the rectum.
In cases of suspected cancer, biopsy of the testes or prostate may be necessary.
The investigation of sexually transmitted diseases
The investigation of sexually transmitted diseases includes:
•examination of discharges
Many sexually transmitted diseases have characteristic symptoms and signs. Physical examination of the external genitalia in men and women, and the vagina, cervix and uterus in women, may reveal some of the characteristic features of these diseases.
Examination of discharges
Samples of vaginal or penile discharges may be taken by means of a swab to examine for evidence of microorganisms and viruses. In women, often three swabs are taken, two from the cervical opening (os) and one from the vagina. The most common organisms that are isolated include Candida, Gonococcus, Chlamydia, Trichomonas and Gardnerella.
Blood tests can provide evidence of a sexually transmitted infection. These include the test for human immunodeficiency virus (HIV), in which antibodies to HIV are indicative of infection. Blood tests can also reveal evidence of infection by hepatitis B and C and syphilis.
GU clinics offer the HIV test on a strictly confidential basis. Because of the consequences of being tested as HIV-positive, patients may be offered pre-test and post-test counseling, irrespective of whether the test is positive or negative.
5.2c Disorders of menstruation and the menopause
The conditions explored in this section are:
•Amenorrhea and oligomenorrhea – primary amenorrhea:
•Amenorrhea and oligomenorrhea – secondary amenorrhea:
–primary ovarian failure
–polycystic ovary syndrome (PCOS)
–dysfunctional uterine bleeding
–uterine fibroids and endometrial polyps
–pelvic inflammatory disease (PID)
•Premenstrual syndrome (PMS)
•Problems during the menopause.
Amenorrhea and oligomenorrhea
Amenorrhea is defined as total lack of menstruation. It may be primary or secondary. Primary amenorrhea means that there has never been an onset of menstruation. This diagnosis is made if the menarche has not occurred by the age of 16.
Secondary amenorrhea indicates a cessation of menstruation. This diagnosis is made when menstruation has ceased for more than 70 days. Oligomenorrhea indicates infrequent periods with a cycle length of greater than 35 days. In general, the causes of oligomenorrhea are the same as those of secondary amenorrhea.
In most cases of primary amenorrhea there is no structural abnormality. There may instead be an inherited tendency to have a late onset of menstruation. There may be other factors, such as chronic illness, an eating disorder or excessive exercise, which have delayed the onset of menstruation. These inhibit the onset of menstruation by causing a reduction in the release of the pituitary hormones LH and FSH.
More rare structural causes of primary amenorrhea include congenital defects of the ovaries, uterus, vagina or hymen. In all but the first of these conditions, the other features of puberty will appear normally. Turner’s syndrome is a relatively common chromosomal disorder in which the affected woman has underdeveloped ovaries, and often first presents with primary amenorrhea and failure to develop the other secondary sexual characteristics of puberty.
Primary amenorrhea is usually investigated if menarche has not occurred by the age of 16. A physical examination is performed, and blood tests are taken to look for FSH, LH and the sex hormones, including testosterone. Prolactin (PRL) levels and thyroid function are also assessed. If it is found that the ovaries are not responding to the pituitary hormones (suggesting congenital disorders of the ovary such as Turner’s syndrome), hormone replacement therapy (HRT) containing estrogen and progestogen is prescribed so that the beneficial effects of estrogen on the bones are maintained.
If the problem lies in factors that lead to underproduction of sufficient pituitary hormones, such as over-exercise or anorexia nervosa, then ideally these factors should first be remedied. In these cases estrogen lack is a real concern, as HRT does not seem to offer the benefit in terms of protection from osteoporosis as might be expected, possibly because of poor nutritional status.
Secondary amenorrhea and oligomenorrhea
The most common cause of secondary amenorrhea is pregnancy. This common cause may actually be a possibility that has been overlooked by the patient, but needs always to be considered in any case of absence of menstrual bleeding.
In most cases of secondary amenorrhea there is no physical abnormality, because most commonly it develops as a response to factors that affect the release of pituitary hormones. Conditions such as chronic illness, eating disorders and over-exercise, already described as causes of primary amenorrhea, can also lead to cessation of periods after a normal menarche. Less seriously, episodes of physical or emotional stress, such as exams or overseas travel, might cause amenorrhea for a short time. Teenage girls are particularly prone to stress-related amenorrhea. For this reason, secondary amenorrhea is usually not investigated until it has persisted for at least six months.
This is a rare and irreversible cause of secondary amenorrhea. In most cases the cause is unknown. In some cases there may be autoimmune damage to the ovaries. In this condition the ovaries simply stop producing follicles, and the woman enters an early menopause (defined as menopause occurring before the age of 40). Women with primary ovarian failure are offered HRT until the age of 50 in order to prevent the development of osteoporosis. Conception may still be possible with assisted conception techniques.
Some cases of amenorrhea are the result of endocrine diseases, for example, hyperthyroidism or excessive prolactin secretion, in which case the treatment is primarily treatment of the underlying cause.
In up to one-third of women at some point in their lives the ovarian follicles do not develop properly. The ovary becomes enlarged, with four or more enlarged but intact follicles (cysts). This situation is often associated with irregularity of menstruation, but is not a cause for concern. However, a subgroup of women with polycystic ovaries may be diagnosed with polycystic ovary syndrome (PCOS), when the condition is associated with weight gain, oligomenorrhea or amenorrhea, excessive body hair in a male distribution and infertility. It is believed that insulin resistance and over-secretion of insulin might be the fundamental problem in this form of PCOS.
This hormonal imbalance is believed to affect the LH surge from the pituitary gland (so preventing rupture of the ovarian follicles and causing infertility) as well as leading to excessive formation of male sex hormones (which cause excessive body hair and also acne). PCOS is associated with a greater than average risk of non-insulin-dependent diabetes mellitus, high blood pressure and cardiovascular disease. There is also a small increased risk of cancer of the womb and of the ovaries.
PCOS is very common, affecting between 5 and 15 percent of women. However, only a few will exhibit the more severe manifestations of the syndrome.
In PCOS, ultrasound examination of the ovaries shows unruptured ovarian follicles and a blood test reveals an imbalance in the levels of FSH and LH and in some cases raised levels of testosterone and PRL.
As part of the treatment for PCOS the patient is advised to lose weight, stop smoking and to increase participation in gentle exercise, as these changes can normalize insulin levels. The antidiabetic drug metformin may be prescribed, as it reduces insulin resistance, particularly in anyone who is classified as overweight according to their body mass index (BMI >25).
If amenorrhea is the primary problem, the combined oral contraceptive pill is prescribed to induce regular menstruation and protect the woman from endometrial cancer.
If fertility is the primary concern, the drug clomiphene may be prescribed to induce ovulation in PCOS. If this fails to help with conception, surgical drilling of the ovaries can reduce the production of unnecessary sex steroid hormones and improve fertility rates.
Excessive male-pattern body hair in PCOS can be treated by means of medication. The oral contraceptive may be effective in reducing the hairiness. Alternatively, the drug cyproterone acetate may be prescribed. This has the effect of opposing the action of the male sex hormones.13
Amenorrhea: comments from a Chinese medicine perspective
In Chinese medicine, amenorrhea (no periods) may be an Empty or a Full condition. The empty conditions include Jing Deficiency, Blood Deficiency, Spleen and Kidney Deficiency, and Liver and Kidney Deficiency. The Full conditions include Cold in the Uterus, Phlegm or Qi/Blood Stagnation. Oligomenorrhea (late periods) might indicate Blood Deficiency, Cold in the Uterus, Kidney Yang Deficiency or Qi Deficiency.
PCOS with its association with weight gain, acne and hirsutism is likely to involve Phlegm Damp and Liver Qi disharmony.