Normal female genital organs. Female genital system
The human reproductive system is a complex of organs through which reproduction occurs. They also determine gender characteristics and perform sexual function. Unlike other organ systems, the reproductive system begins to function only when the human body is ready to participate in childbirth. This occurs during puberty.
Sexual demorphism is pronounced; The human reproductive system is responsible for the formation of differences, that is, the male and female sexes differ from each other in internal and external structure.
The reproductive system, the structure of which allows men and women to produce gametes using the gonads (sex glands), is divided:
- on the external genitalia;
- internal genital organs;
Male reproductive system, histology of internal organs
The male reproductive system is represented by external (penis, scrotum) and internal (testicles and their appendages) organs.
Testicles (testes, testicles) are gonads, a paired organ within which spermatogenesis (maturation of sperm) occurs. The testicular parenchyma has a lobular structure and consists of seminiferous tubules that open into the epididymal canal. The spermatic cord approaches the other edge. During the perinatal period, the testicles are located in the abdominal cavity, then normally descend into the scrotum.
The testes produce a secretion that is part of sperm, and also secrete androgen hormones, mainly testosterone, and in small quantities estrogen and progesterone. Together, these hormones regulate spermatogenesis and the development of the entire organism, stopping the growth of bones in length at a certain age. Thus, the formation of the entire organism is influenced by the reproductive system, the organs of which not only have a reproductive function, but also participate in humoral regulation.
In the testes there is a constant production of sperm - male gametes. These cells have a movable tail, thanks to which they are able to move against the flow of mucus in the woman’s genital tract towards the egg. Mature sperm accumulate in the epididymis, which has a system of tubules.
The accessory sex glands also play a role in the formation of sperm. The prostate gland secretes some components of sperm and substances that stimulate spermatogenesis. The muscle fibers present in the gland compress the urethra during sexual arousal, preventing urine from entering during ejaculation.
Cooper's (bulbourethral) glands are two small formations located at the root of the penis. They secrete a secretion that dilutes sperm and protects the urethra from the inside from the irritating effects of urine.
External male genitalia
The male reproductive system also includes the external genitalia - the penis and scrotum. The penis consists of a root, a body and a head; inside there are two cavernous and one spongy body (the urethra lies in it). In a state of sexual arousal, the corpus cavernosum fills with blood, resulting in an erection. The head is covered with thin movable skin - the foreskin (prepuce). It also contains glands that secrete a slightly acidic secretion - smegma, which protects the body from the penetration of bacteria.
The scrotum is the outer, musculocutaneous membrane of the testes. The latter performs protective and thermoregulatory functions.
Secondary male sexual characteristics
Men also have secondary sexual characteristics, which are indicators of puberty and gender differentiation. These include male-type facial and pubic hair growth, armpit hair growth, as well as growth of laryngeal cartilage, which leads to a change in voice, with the thyroid cartilage coming forward, forming the so-called Adam's apple.
Female reproductive system
The female reproductive system has a more complex structure, since it performs not only the function of producing gametes - fertilization occurs in it, and then the development of the fetus with its subsequent birth. The internal organs are represented by the ovaries, fallopian tubes, uterus and vagina. External organs are the labia majora and minora, hymen, clitoris, Bartholin's and mammary glands.
External female genitalia
The female reproductive system is externally represented by several organs:
- The labia majora are folds of skin with fatty tissue that perform a protective function. Between them there is a genital gap.
- The labia minora are two small folds of skin, resembling a mucous membrane, located under the labia majora. Inside they have muscle and connective tissue. The labia minora cover the clitoris on top and form the vestibule of the vagina below, into which the opening of the urethra and gland ducts open.
- The clitoris is a formation in the upper corner of the genital opening, measuring only a few millimeters in size. In its structure it is homologous to the male genital organ.
The entrance to the vagina is covered by the hymen. In the groove between the hymen and the labia minora there are Bartholin's glands, one on each side. They secrete a secretion that acts as a lubricant during sexual intercourse.
Together with the vagina, the external genitalia are a copulatory apparatus designed for the introduction of the penis and sperm, as well as the removal of the fetus.
Ovaries
The female reproductive system also consists of a complex of internal organs located in the pelvic cavity.
The ovaries are the sex glands, or gonads, a paired oval-shaped organ located to the left and right of the uterus. During embryonic development, they form in the abdominal cavity and then descend into the pelvic cavity. At the same time, primary germ cells are laid, from which gametes will subsequently be formed. It is the endocrine glands that regulate the reproductive system, the histology of which is such that there are both organs that produce hormones and target organs that respond to humoral influences.
After maturation, the reproductive system begins to work, as a result of which ovulation occurs in the ovaries: at the beginning of the cycle, the so-called Graafian vesicle matures - a sac in which the female gamete - the egg - is formed and grows; Approximately in the middle of the cycle, the bubble bursts and the egg is released.
In addition, the ovary, being an endocrine gland, produces the hormone estradiol, which is involved in the formation of the female body and many other processes, as well as in small quantities testosterone (male sex hormone). In place of the burst follicle, another gland is formed - the corpus luteum, the hormone of which (progesterone) ensures the safety of pregnancy. If fertilization does not occur, the corpus luteum dissolves, forming a scar.
Thus, the reproductive system regulates the physiological development of the body. It is the sequence of work of the follicular system and the corpus luteum system that forms the menstrual cycle, which lasts on average 28 days.
Fallopian tubes
Funnel-shaped tubes extend from the corners of the uterine fundus to the ovaries, the wide part of which faces the ovary and has a fringe-like edge. On the inside, they are covered with ciliated epithelium, that is, the cells have special cilia that make wave-like movements that promote fluid flow. With their help, the egg released from the follicle moves through the tube towards the uterus. This is where fertilization occurs.
Uterus
The uterus is a hollow muscular organ in which the embryo develops. This organ has a triangular shape; it has a bottom, a body and a neck. The muscular layer of the uterus thickens during pregnancy and is involved in childbirth, as its contraction provokes expulsion of the fetus. The mucous inner layer grows under the influence of hormones so that the embryo can attach to it at the very beginning of its development. If fertilization does not occur, then at the end of the menstrual cycle the membrane is torn away and bleeding occurs (menstruation).
The cervical canal (cervical canal) passes into the vagina and secretes mucus, which creates a barrier that protects the uterus from environmental influences.
Vagina
The vagina is a muscular organ in the shape of a tube, covered from the inside with a mucous membrane; located between the cervix and the genital opening. The walls of the vagina are elastic and stretch easily. The mucous membrane is populated by specific microflora that synthesize lactic acid, due to which the urinary reproductive system is protected from the introduction of pathogenic microorganisms.
Secondary sexual characteristics of women
Women, just like men, have secondary gender characteristics. During puberty, they experience growth of hair on the pubis and in the armpits, a female body type is formed due to fat deposits in the pelvis and hips, while the pelvic bones extend in the horizontal direction. In addition, women develop mammary glands.
Mammary gland
The mammary glands are derivatives of the sweat glands, but perform the function of milk production during feeding of the baby. The rudiments of the glands are formed during the perinatal period in all people. In men, they remain in their infancy throughout their lives, since their reproductive system is not designed for lactation. In girls, the mammary glands begin to grow after the menstrual cycle is established and develop to their maximum towards the end of pregnancy.
In front of the gland there is a nipple into which the milk ducts open. Milk begins to be secreted in the alveoli under the influence of the hormone prolactin, produced by the pituitary gland as a reflex in response to irritation of nipple receptors during sucking. Lactation is also regulated by oxytocin, a hormone that contracts smooth muscle, allowing milk to move through the milk ducts.
After childbirth, colostrum is produced - a yellow secretion containing an increased amount of immunoglobulins, vitamins and minerals. On days 3-5 of lactation, milk production begins, the composition of which changes with the age of the child. On average, lactation lasts 1-3 years. After its completion, partial involution of the glands occurs.
Thus, the female reproductive system has a complex reproductive function, ensuring gestation and birth of the fetus, as well as its subsequent feeding.
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Do you want to have a child
In the life of every family, sooner or later there comes a time when spouses have to decide whether to have a child or not. It is better if you think about this in advance, before pregnancy occurs, that is, conceiving a child will be planned.
Sexual desire is not always subordinated to the desire to have a child, and often due to insufficient medical literacy, and sometimes due to the lack of accessible contraceptives, unwanted pregnancy occurs.
In our country, the number of abortions exceeds the number of births, and many children are born after much deliberation by parents - to leave the pregnancy or terminate it. This psychological state of the expectant mother interferes not only with her developing a natural feeling of love and tenderness for her unborn child, but also with the normal course of pregnancy.
Of course, things may be different for you. You have carefully weighed the upcoming difficulties and are aware that with the appearance of a new, small and most important person in the family, you will have a significant increase in worries, you will have to largely abandon the existing way of life and rhythm of life, and give up some attachments and habits. But you think that all the difficulties will be more than compensated by the happiness of motherhood and fatherhood, and you are right. We can assume that psychologically you are truly ready to give birth to a child. He will be desired, and this is one of the most important factors in his normal development and upbringing.
However, there are medical aspects of family planning that are sometimes completely ignored.
When expecting a child, you are sure in advance that he will be the most beautiful, the smartest, the happiest. This is how your child will most likely turn out to be for you, especially if he is healthy. But a child’s health depends on many reasons, most of which can be predicted and targeted. Let's talk about this.
But in order to have a clear idea of the processes that occur in the bodies of women and men and ensure procreation, let us at least get acquainted with the anatomy and physiology of the female and male reproductive systems.
In the genital organs of women there are external And internal.
These are the pubis, labia majora and minora, clitoris, vestibule of the vagina, glands of the vestibule, hymen (separating the external genitalia from the internal) and the anterior perineum.
The pubis is located in the lowest part of the anterior abdominal wall. With the onset of puberty, its surface becomes covered with hair.
The labia majora are formed by two folds of skin extending from the pubis, where their anterior commissure occurs. At the perineum they converge into the posterior commissure. The skin of the labia majora is covered with hair.
The labia minora are located between the labia majora. In front they form the small flesh of the clitoris, and then behind they become narrower, thinner, merging with the labia majora in their posterior third.
The clitoris is similar in structure to the male penis, but is much smaller in size. It is formed by two cavernous bodies, and on top is covered with delicate skin rich in sebaceous glands. During sexual arousal, the corpus cavernosum fills with blood, which causes an erection of the clitoris - it tenses and increases in size.
The vestibule of the vagina is a space limited in front and above by the clitoris, behind and below by the posterior commissure of the labia majora, and on the sides by the labia minora. The bottom of the vestibule is formed by the hymen or its remnants surrounding the entrance to the vagina.
In the vestibule are the external opening of the urethra, located slightly back and down from the clitoris, and the excretory ducts of the small and large glands of the vestibules. In the lateral sections of the vestibule, under the base of the labia majora, there are the cavernous bodies of the vestibular bulbs, the structure of which is similar to the structure of the cavernous bodies of the clitoris.
The large glands of the vestibule (Bartholin's glands) are complex tubular formations with a diameter of about 1 cm. Their excretory ducts open at the junction of the labia majora and the labia minora. The glands secrete a liquid secretion that moisturizes the vestibule of the vagina.
The large glands of the vestibule are located in the thickness of the posterior third of the labia majora, one on each side.
The hymen is a thin connective tissue plate that has one (less often several) opening through which the secretions of the internal genital organs and menstrual blood are released. During the first sexual intercourse, the hymen is usually torn; in women who are sexually active but have not given birth, its edges look like fimbriae - the so-called hymenal papillae. After childbirth, these papillae are greatly smoothed out.
Between the posterior commissure of the labia majora and the anal opening is the anterior perineum, and between the anal opening and the tip of the coccyx is the posterior perineum. When an obstetrician-gynecologist talks about the perineum, he usually means the anterior perineum, since its posterior part is not significant for obstetrics.
The internal female genital organs include - the vagina, the uterus and its appendages - the uterine (fallopian) tubes and ovaries, as well as their ligaments (round and broad ligaments of the uterus, proper and pendulous ligaments of the ovaries).
The vagina is a tube 10-12 cm long, running in the direction from bottom to top and somewhat back from the vestibule of the vagina to the uterus. The upper part of the vagina connects to the cervix, forming four fornixes - anterior, posterior and two lateral.
The vaginal wall has a thickness of 0.3-0.4 cm, it is elastic and consists of three layers: internal (mucosal), middle (smooth muscle) and external (connective tissue). During puberty, the mucous membrane forms folds, mainly located transversely. The folding of the mucous membrane decreases after childbirth, and in many women who have given birth it is practically absent.
The vaginal mucosa has a pale pink color, which becomes bluish during pregnancy.
The middle, smooth muscle layer is highly extensible, which is especially important during childbirth. External, connective tissue, connects the vagina with neighboring organs - the bladder and rectum.
The uterus is shaped like a pear, compressed in the anteroposterior direction. This is a hollow organ. The weight of the uterus in a nulliparous mature woman reaches 50-100 g, length - 7-8 cm, greatest width (at the bottom) - 5 cm, wall thickness - 1-2 cm.
The uterus is divided into three sections, the cervix, the body and the border between them - the so-called isthmus.
The cervix accounts for approximately one third of the length of this organ. Part of the cervix is located in the vagina, and therefore is called the vaginal part of the cervix. In a nulliparous woman, this part is shaped like a truncated cone (subconical neck), while in a woman who has given birth, it resembles a cylinder.
The cervical canal, which has the appearance of a spindle, runs through the entire cervix. This form best promotes retention of the mucous plug - the secretion of the glands of the cervical canal - in its lumen. This mucus has bactericidal properties, that is, it kills bacteria and thereby prevents infection from entering the uterine cavity.
The cervical canal opens into the uterine cavity through the internal os, and into the vagina through the external os. The external os of the cervical canal in a nulliparous woman looks like a point, and in a woman who has given birth, it looks like a transverse slit due to small tears during childbirth.
From the isthmus of the uterus at the end of pregnancy, the lower uterine segment is formed - the thinnest part of the uterus during childbirth.
The body of the uterus is located above the isthmus, its apex is called the fundus.
The wall of the uterus consists of three layers: the inner layer is the mucous membrane (endometrium), the middle layer is the muscular layer, and the outer layer is the serous layer, or peritoneum. The mucous membrane, in turn, is divided into two more layers - basal and functional.
As we have already said, the uterine appendages are the fallopian tubes, ovaries and ligaments. The fallopian tubes extend from the bottom of the uterus (its corners) towards the side walls of the pelvis.
The fallopian tubes are essentially oviducts through which the egg enters the uterine cavity. The average length of the fallopian tube is 10-12 cm. Its lumen in the wall of the uterus is only 0.5 mm, but gradually increases, reaching 5 mm at the end (in the funnel).
From the funnel there are numerous fimbriae - fimbriae. The fallopian tubes contract in waves, the cilia lining them from the inside vibrate, due to which the egg moves into the uterine cavity.
The ovary is a paired organ that is a female reproductive gland with an average size of 3x2x1 cm. Eggs grow and develop in the ovary. It also produces female sex hormones - estrogens and progesterone.
Hormones (Greek hormao - excite, encourage) are biologically active substances that are produced by endocrine glands (Greek endon - inside, krino - secrete) and enter directly into the blood. The ovary is one of these glands. Sex hormones regulate the activity of the reproductive system.
A more or less constant position of the internal genital organs is possible due to the action of suspending, fixing and supporting devices. These are paired connections. The uniqueness of their functions is such that, while holding the uterus and appendages in a certain position, they at the same time allow them to maintain quite significant mobility, which is necessary for the normal development of pregnancy and the course of labor.
A woman's internal genital organs are located in the pelvic cavity (that is, in the lower pelvis) - the space between the sacrum and coccyx at the back, the pubic symphysis at the front and the ischial bones at the sides. In addition to the female genital organs, the pelvis also contains the rectum and bladder when it is not filled with urine or is almost empty. The pelvis of an adult woman, compared to a man’s, is more voluminous and wider, but at the same time less deep.
A woman’s body, and primarily her reproductive system, prepares monthly for pregnancy. These complex, rhythmically repeating changes that occur in the body are called the menstrual cycle.
Its duration varies among different women, most often - 28 days, less often - 21 days, very rarely - 30-35 days.
What exactly happens in a woman’s body during the menstrual cycle?
Under the influence of hormones from the hypothalamus and pituitary gland (parts of the brain), an egg grows and develops in one of the ovaries (Figure 3). It matures in a follicle filled with fluid.
As the follicle grows, the cells lining its inner surface produce increasing amounts of estrogenic hormones. Under the influence of these hormones, the thickness of the endometrium gradually increases.
When the follicle reaches 2-2.5 cm in diameter - and this happens in the middle of the menstrual cycle (on the 10-14th day, depending on its duration) - it ruptures. This phenomenon is called ovulation, the egg is released from the follicle into the abdominal cavity.
After ovulation, a so-called corpus luteum is formed at the site of the follicle, which secretes progesterone, the hormone that maintains pregnancy. Under its influence, changes occur in the endometrium, due to which the uterine mucosa becomes capable of receiving an embryo.
The egg, as a result of complex biological and chemical processes, enters the fallopian tube, where fertilization can occur. If this does not happen, the corpus luteum undergoes reverse development, and the concentration of hormones (progesterone and estrogen) decreases significantly.
Maturation of the egg in the ovary.
1 - primary follicles, 2 - growing follicle, 3 - mature follicles, 4 - egg after ovulation, 5 - collapsed mature follicle, 6 - corpus luteum, 7 - follicle that has undergone reverse development
Basal temperature curve
a - two-phase cycle (a rise in temperature is observed after ovulation),
b - anovulatory cycle (no rise in temperature).
Eventually, most of the endometrium is shed and menstrual bleeding, or menstruation, occurs, lasting 3 to 5 days. In place of the corpus luteum, a white body is formed, and the growth of the next follicle begins in the ovary.
This process is called the ovarian cycle. It is not visible, and its progress can be judged only by using special research methods (determining the concentration of hormones in the blood, ultrasound examination of the ovaries, functional diagnostic tests, etc.). But under the influence of the changes that occur in the ovary, changes occur in other parts of the woman’s reproductive system, the results of which can be detected.
So, if the reproductive system functions correctly, then a woman, in the absence of pregnancy, regularly experiences menstruation. As you can see, the onset of menstruation does not mean the beginning, but the end of the menstrual cycle. It signals the death of an unfertilized egg, the attenuation of those functional changes that were associated with the body’s preparation for pregnancy. Therefore, it is possible to become pregnant during the first menstrual cycle, when there has not yet been a single menstruation.
If the egg is fertilized, menstruation stops.
The processes occurring in the ovary and uterus during the menstrual cycle affect the entire body. The activity of the nervous and cardiovascular systems, thermoregulation, and metabolism change. Many women notice this by increased irritability, drowsiness and fatigue before menstruation, which are replaced by cheerfulness and a surge of strength after it.
If, throughout the entire menstrual cycle, you measure the temperature in the rectum (basal, or rectal temperature) every day at the same time, for example in the morning immediately after waking up, and plot the results on a graph (Figure 4), you can get a kind of curve. In a healthy woman, it has a two-phase character until the 12-14th day, it goes lower, and in the next 7-10 days it goes above 37 ° C (37.1-37.5 ° C). An increase in temperature indicates the beginning of ovulation and its continuation. It must be said that measuring rectal temperature is used to determine days when pregnancy cannot occur.
Although in childhood (from birth to 8-9 years) a girl’s genitals gradually increase in size, this is a period of physiological rest. There is no menstrual function, eggs in the ovaries do not grow or mature. Few female sex hormones are produced, and their effect on the body is minimal. Therefore, there are no secondary sexual characteristics (hair growth, development of mammary glands).
During puberty (from 8-9 to 18 years), the girl gradually turns into a woman, at 8-9 years the bony pelvis becomes wider and fatty tissue is deposited on the hips, at 9-10 years the nipples grow, at 10-11 years they become larger mammary glands, at 11 years old pubic hair appears, at 12-13 years old the nipples become pigmented and the mammary glands continue to grow, at 12-14 years old menstruation appears, at 13-14 years old hair appears in the armpits.
Puberty in women lasts until approximately 45 years of age. From 20 to 35 years is the most favorable time for pregnancy; the body is best prepared for this.
In the next five years - from 45 to 50 years - the functioning of the reproductive system gradually fades away. Sometimes the menstrual cycle is disrupted due to changes in the timing of follicle maturation and the onset of ovulation. At this time, due to the restructuring of the endocrine system, menopausal disorders often occur (increased nervousness, a feeling of a rush of blood to the head, severe sweating, etc.).
During the aging period, menstrual function stops completely, and the uterus and ovaries decrease in size - their reverse development occurs.
During reproductive age, which lasts an average of 25-30 years for a woman, various gynecological diseases often arise. Many of them can cause infertility.
To prevent, timely detect and treat them, you need to regularly visit a gynecologist, even if you feel completely healthy.
The first visit to the antenatal clinic, at a minimum, should take place shortly after the start of sexual activity. The doctor will give you the necessary advice on sexual hygiene, answer questions that have arisen in connection with the new condition of the girl who has become a woman, and recommend a method of birth control.
Already at the first visit to the antenatal clinic, asymptomatic diseases and deviations from the norm are sometimes discovered, which can then cause infertility.
Let's look at some of them.
During the period of formation of menstrual function, periods are quite often irregular. After the first menstruation, 2-3 months or more may pass before the next one occurs.
If this period is not too long, there is no need to worry; the body establishes certain relationships between the higher and lower stages of the menstrual cycle mechanism - the parts of the brain (hypothalamus and pituitary gland) that regulate the production of hormones, and the genital organs (ovaries and uterus).
But if the menstrual cycle does not stabilize by the age of 15-16, menstruation is painful, profuse, and does not stop for a long time, so that the hemoglobin content in the blood decreases and anemia develops (these are cyclic uterine bleeding if their onset coincides with the beginning of menstruation, and acyclic if they occur at any time and it is impossible to establish the rhythm of the cycle), or, on the contrary, scanty, rare and short (oligomenorrhea (Greek oligos - few, insignificant), or absent altogether (amenorrhea), you should definitely consult a doctor. Similar menstrual irregularities can occur in women and other age groups.
What are the causes of menstrual irregularities?
There are many of them: these are malformations and anomalies in the position of the female genital organs, inflammatory diseases, especially the uterus and its appendages, abortions with complications, abnormal course of childbirth and the postpartum period, obesity, tumors of the genital organs, disruption of the functioning of the endocrine glands (ovaries, adrenal cortex, thyroid gland) or brain centers, chronic diseases of other organs and systems, stress, severe nervous shock, unfavorable environmental conditions, in particular harmful production factors, stay in other climatic zones.
If you have menstrual irregularities, you should consult a doctor without delay - it is easier to cope with any disease if you start treatment on time.
In addition, diseases, one of the symptoms of which is menstrual irregularity, if left untreated, can further lead to infertility.
Before sexual activity begins, a healthy woman has fairly strong biological barriers that prevent infection of the genital tract and organs. This is the acidic reaction of the vaginal contents, which is fatal to many pathogenic bacteria, the specific microflora of the vagina, which also kills them, and, finally, the mucous plug of the cervix, which has bactericidal properties.
However, with the onset of sexual activity, the protective functions of vaginal contents are reduced, which creates conditions for infection to penetrate through the vagina into the cervix, and from there into the uterus and further into the tubes and ovaries.
Neighboring organs, such as an inflamed appendix, can also become a source of infection.
Some microorganisms enter the genital tract of a woman during sexual intercourse, for example, Trichomonas is a protozoan that has an organelle of movement - a flagellum, thanks to which it can penetrate the uterus, its tubes, and even the abdominal cavity.
In men, trichomoniasis is most often asymptomatic, and they can infect women without even knowing that they are sick. But you can become infected with trichomoniasis by using a towel that was used to wipe a sick person.
Trichomonas are also dangerous because they can “transport” other pathogens. Spermatozoa are the same “carriers”. Moreover, they can become infected both in the body of a man and in the vagina of a woman.
When infected with Trichomonas, whitish or purulent foamy discharge from the genital tract, itching and burning of the external genitalia, a feeling of heaviness in the lower abdomen, and pain during sexual intercourse appear.
Infection with gonococcus, which is often carried by Trichomonas, and more often by sperm, leads to gonorrhea - purulent inflammation of the urethra, the mucous membrane of the cervical canal and fallopian tubes. As a rule, as a result of inflammation, the patency of the latter is impaired and infertility develops.
The disease begins with the appearance of pain and burning during urination, yellow-green discharge from the urethra and vagina. Then the temperature rises, pain occurs in the lower abdomen, which usually indicates the spread of the pathological process to the fallopian tubes.
The vaginal mucosa may become infected with yeast. In this case, white plaques appear on it, under which ulcers are located. A thick, curd-like leucorrhoea is discharged, and itching and burning of the external genitalia occur. If the disease began during pregnancy and the woman was not treated, the child may become infected while passing through the birth canal and develop thrush - a fungal infection of the oral mucosa.
Often, various parts of a woman’s reproductive system are affected by the herpes virus. At the same time, the temperature may rise, and painful ulcers appear on the mucous membrane of the external genital organs (if they are affected), causing itching and a burning sensation.
If you notice these symptoms, consult your doctor immediately. The disease must be cured in its acute stage. Otherwise, it will take a chronic course, and then it will be much more difficult to cope with it.
The danger of chronic inflammation of the genital organs, and especially the uterine appendages - tubes and ovaries, is that this very often leads to infertility.
In addition, chronic inflammatory processes in the genital organs are also important for the course of pregnancy.
Firstly, the risk of spontaneous interruption increases.
Secondly, intrauterine infection of the fetus is possible, which can lead to dire consequences for the child.
Prevention of inflammatory diseases of the genital organs consists of observing hygienic requirements, avoiding hypothermia, eliminating foci of chronic infection (sore teeth, chronic tonsillitis, etc.).
You also need to know that inflammation of the uterine appendages is promoted by inadequate sex life, for example, when preventing pregnancy by interrupted sexual intercourse or when the husband is impotent.
Lack of sexual arousal causes blood to stagnate in the genitals, facilitating the development of infection.
One of the common malformations is a continuous hymen, in the presence of which menstrual blood and the secretion of the glands of the cervical canal are not released to the outside.
The pathology is usually discovered after the onset of menstruation, when once a month the girl feels pain in the lower abdomen and a feeling of discomfort in the vagina. In this case, there is no menstrual flow.
Treatment of this anomaly is carried out surgically, the edges of the hymen are cut and trimmed.
In the complete absence of the vagina or part thereof, as well as the occlusion of the vagina as a result of inflammation suffered in the prenatal period or early childhood, pregnancy is impossible due to the lack of its connection with the uterus.
If there are no other anomalies in the development of the genital organs, surgical restoration of the vagina makes possible not only sexual activity, but also pregnancy.
Developmental defects such as duplication, or bicornuity, of the uterus usually do not prevent pregnancy, and it can occur alternately in one or the other uterus (horn).
A rudimentary (undeveloped) uterus, as well as the complete absence of it or the ovaries, naturally excludes the possibility of pregnancy.
With abnormal development of the fallopian tubes, underdevelopment or absence of one of them is more often observed. In this case, a single tube may be quite sufficient for pregnancy to occur.
Interestingly, in the absence of a tube and ovary on opposite sides (for example, when they are surgically removed), pregnancy is also possible. In this case, the egg enters the tube, having traveled a considerable distance in the abdominal cavity.
Of the anomalies in the position of the genital organs in young women, the most common is retroreflexia of the uterus (its deviation back), which is congenital or can occur as a result of previous inflammatory diseases of the pelvic organs. The deviation of the uterus back is also facilitated by infantilism, in which, as with an asthenic constitution, the ligamentous apparatus that holds the uterus in its normal position is weakened.
Retroreflexia can cause infertility due to the displacement of the cervix and its removal from the posterior vaginal fornix, where sperm is mainly collected after ejaculation.
If the uterus remains mobile (there is no fixed retroreflexion), gynecological massage is used, which helps restore the normal position of the organ.
Fixed retroreflexia is usually a consequence of an inflammatory process in the pelvis and requires anti-inflammatory treatment, and in the presence of severe pain (especially during menstruation), surgical correction of the abnormal position of the uterus.
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The structure of the female reproductive system
The female reproductive system consists of the genital organs, mammary glands, some parts of the brain and endocrine glands that regulate the functioning of the genitals.
The female genital organs are divided into internal and external. External organs: labia, vagina, perineum. Internal organs: uterus, cervix, fallopian tubes, ovaries.
Vagina is a muscular organ that starts from the entrance to the vagina and ends at the cervix. The cells of the vaginal mucosa contain their own substance - glycogen, which is used by the vaginal microflora. This is how lactic acid is formed, which imparts protective properties to vaginal secretions and prevents pathogenic microorganisms from entering the woman’s reproductive system.
Uterus is a hollow muscular organ that serves as the site of fetal development. Consists of the cervix and body. The cervix is a canal approximately 4 cm long. It consists of the vaginal part of the cervix, “facing” the vagina and having an opening - the internal os. During colposcopy and speculum examination, the gynecologist evaluates the vaginal part of the cervix. The supravaginal or uterine part of the cervix opens into the uterine cavity by the internal uterine os. The cells of the mucous membrane of the cervical canal secrete mucus, which has protective properties and prevents the penetration of various microorganisms into the uterine cavity. Before ovulation, these cells produce more liquid mucus, which facilitates the penetration of sperm into the uterine cavity (). During childbirth, the “birth canal” is formed by the vagina and cervical canal, through which the fetus moves.
In the body of the uterus there is a cavity that has the shape of a triangle in the frontal plane. The wall of the uterus contains three layers of muscle cells. The inside of the uterus is “lined” with a mucous membrane - the endometrium. Under the influence of hormones released by the ovaries, the endometrium changes monthly (menstrual cycle). The main function of the uterus is to carry a pregnancy. In the uterine cavity, the fertilized egg attaches and further develops the fetus ().
The fallopian tubes they start from the corners of the uterine cavity and are about 10 cm long. There are two openings in the tube: the wider one opens into the abdominal cavity and forms the funnel of the fallopian tube; the narrower one is the mouth of the tube, opening into the uterine cavity.
The funnel of the fallopian tube ends in fimbriae, which are necessary to “capture” the egg that enters the abdominal cavity after ovulation. On the inner surface of the fallopian tubes there are cells with cilia, which, with wave-like movements, promote the advancement of the embryo to the uterine cavity (). Thus, the transport function is the main function of the fallopian tubes.
Ovaries- female reproductive glands. They are located on the sides of the uterus and “contact” with the funnel of the fallopian tube, or rather with the fimbriae. The ovaries contain follicles, which are round-shaped formations filled with fluid. It is there, in the follicle, that the egg is located, which, after fertilization, gives birth to a new organism (). In addition, the ovaries produce female sex hormones, which regulate the functioning of not only the reproductive system, but also the entire woman’s body.
Function of the female reproductive system
The main function of the female reproductive system is reproductive function. This means that the conception of a new organism and its gestation occurs in the woman’s body. This function is performed through the interaction of several organs related to the female reproductive system. This interaction is ensured by hormonal regulation. It is this regulation that is the main link in the implementation of the reproductive function of the female body.
The pituitary gland, located in the brain, is one of the highest departments of hormonal regulation in all internal organs and systems in the human body. The pituitary gland secretes hormones that regulate the functioning of other endocrine glands - the gonads (LH and FSH), the thyroid gland (TSH - thyroid-stimulating hormone), and the adrenal glands (ACTH - adrenocorticotropic hormone). The pituitary gland also secretes a number of hormones that regulate the functioning of the genital organs (oxytocin), the urinary system (vasopressin or antidiuretic hormone), the mammary gland (prolactin, oxytocin), and the skeletal system (GH or growth hormone).
The functioning of the reproductive system is regulated by several “main” hormones secreted by the pituitary gland: FSH, LH, prolactin. FSH - follicle-stimulating hormone - acts on the process of follicle maturation. Thus, with insufficient/excessive concentrations of this hormone, the process of follicle maturation is disrupted, which can lead to infertility (). LH - luteinizing hormone - is involved in ovulation and the formation of the corpus luteum. Prolactin (milk hormone) affects milk secretion during lactation. Prolactin belongs to the hormones antagonists (competitors) of FSH and LH, i.e. An increase in the concentration of prolactin in a woman’s body causes disruption of the ovaries, which can lead to infertility ().
In addition, the functioning of a woman’s reproductive system is regulated by hormones secreted by other endocrine glands: thyroid hormones - T4 (thyroxine), T3 (triiodothyronine); adrenal hormones - DHEA and DHEA-S. Dysfunction of these endocrine glands leads to disruption of the reproductive system and, accordingly, to infertility ().
Cyclic changes in a woman’s body or the menstrual-ovarian cycle
In a woman’s body, every month there is a change in the lining of the uterus (menstrual cycle) and a change in the ovaries (ovarian cycle). Thus, it is correct to talk about the menstrual-ovarian cycle. The menstrual-ovarian cycle lasts from the first day of menstruation to the first day of the next menstruation (from 21 to 35 days).
The ovarian (ovarian) cycle consists of follicle maturation (folliculogenesis), ovulation and formation of the corpus luteum.
Under the influence of the hormone FSH, at the beginning of the menstrual cycle, the maturation of follicles in the ovary begins - the so-called follicular phase of the menstrual cycle. FSH acts on the primary follicles, which leads to their growth. Typically, several primary follicles begin to grow, but closer to the middle of the cycle, one of the follicles becomes the “leader”. As the leading follicle grows, its cells begin to produce the hormone estradiol, which causes thickening of the uterine mucosa.
In the middle of the menstrual cycle, when the follicle reaches 18-22 mm, the pituitary gland secretes luteinizing hormone - LH (ovulatory peak), leading to ovulation (rupture of the follicle and release of the egg into the abdominal cavity). Then, again under the influence of LH, the corpus luteum is formed - the endocrine gland, which secretes progesterone - the “pregnancy hormone”. Under the influence of progesterone, the lining of the uterus changes (the luteal phase of the cycle), which prepares it for pregnancy. Thus, infertility can also occur due to insufficient function of the corpus luteum.
The menstrual cycle is a change in the lining of the uterus (endometrium) that occurs along with the ovarian cycle. During the follicular phase of the cycle, the endometrium thickens (under the influence of the hormone estradiol). After ovulation, the corpus luteum hormone (progesterone) causes endometrial cells to accumulate large amounts of nutrients for the embryo - the luteal phase of the cycle.
In the absence of fertilization, rejection of the uterine mucosa occurs - menstruation. Along with menstruation, the maturation of primary follicles occurs - a new menstrual cycle.
Changes in other organs and systems
Along with changes in the genitals as a result of the action of hormones, cyclic changes also occur throughout the woman’s body.
This can be especially noticeable in the second phase of the menstrual cycle, when the body “prepares” for a possible pregnancy. Progesterone causes fluid and salt retention in the body, increasing appetite. The consequences of this process are weight gain, engorgement of the mammary glands, and bloating. In addition, due to slight swelling of the brain tissue, headache, inertia of thinking, drowsiness or insomnia are possible. Sometimes mood swings occur - tearfulness, irritability, fatigue, lethargy and apathy. When menstruation occurs, such changes in a woman’s body disappear.
This example illustrates the basic way energy is converted into
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the cell had to create such a “coupling” of processes during evolution
special molecular "energy-converting" devices that
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The mechanisms of energy transformation in biological structures are associated with conformational transformations of special macromolecular complexes, such as reaction centers of photosynthesis, H - ATPase of chloroplasts and mitochondria, bacteriorhodopsin. Of particular interest are the general characteristics of the efficiency of energy conversion in such macromolecular machines. Thermodynamics of biological processes is designed to answer these questions.
The female genital organs are divided into external and internal.
External genitalia.
The external genitalia in women include: the pubis, labia majora and minora, Bartholin glands, clitoris, vestibule of the vagina and the hymen, which is the boundary between the external and internal genitalia.
PUBIS - a triangular elevation covered with hair, located above the womb. The boundaries are: from above - the transverse skin groove; from the sides - inguinal folds.
In women, the upper border of the pubic hair looks like a horizontal line.
LABIA MAJORA - two folds of skin that limit the genital slit on the sides. In front they pass into the skin of the pubis, in the back they merge into the posterior commissure. The skin on the outer surface of the labia majora is covered with hair, contains sweat and sebaceous glands, under it there are vessels in the subcutaneous fatty tissue , nerves and fibrous fibers, and in the posterior third - large glands of the vestibule (Bartholin's glands) - round alveolar-tubular,
the size of a bean gland. Their excretory ducts open in the groove between the labia minora and the hymen, and their secretion is released during sexual arousal.
The space between the posterior commissure and the anal opening is called the inter-
ity. In an anatomical sense, the perineum is a muscular-fascial plate covered on the outside with skin. Its height is on average 3-4 cm.
LABIA MINARA - the second pair of longitudinal skin folds. They are located medially from the labia majora and are usually covered by the latter. In front, the labia minora bifurcate into two legs on each side, which, merging, form the foreskin of the clitoris and the frenulum of the clitoris. Posteriorly, the labia minora merge with large.Thanks to the
The labia minora are the organs of sexual sense due to the presence of blood vessels and nerve endings.
CLITORIS. Outwardly noticeable as a small tubercle in the anterior corner of the genital gap between the fused legs of the labia minora. The clitoris has a head, a body consisting of cavernous bodies and legs that are attached to the periosteum of the pubic and ischial bones. Abundant blood supply and innervation make it the main organ of sexual sensation women.
THE VAGINA VESTRUCTURAL is a space bounded in front by the clitoris, behind by the posterior commissure of the labia, on the sides by the inner surface of the labia minora, and above by the hymen. The external opening of the urethra and the excretory ducts of the Bartholin glands open here.
The hymen is a connective tissue membrane that covers the entrance to the vagina in virgins. Its connective tissue base contains muscle elements, blood vessels and nerves. There must be a hole in the hymen. It can be of any shape. After defloration, the hymenal papillae remain from the hymen, after childbirth - myrtle-shaped papillae.
Internal genital organs.
These include: the vagina, uterus, fallopian tubes and ovaries.
VAGINA is a well-stretchable, muscular-elastic tube. It runs from the front and bottom to the back and top. Starts from the hymen and ends at the place of attachment to the cervix. Average dimensions: length 7-8 cm (back wall 1.5-2 cm . longer), width 2-3 cm. Due to the fact that the front and back walls of the vagina are in contact, in cross section it has the shape of the letter H. Around the vaginal part of the cervix, which protrudes into the vagina, the walls of the vagina form a vaulted formation. It is customary to divide it on the anterior, posterior (deepest) and lateral fornix. The vaginal wall consists of three layers: mucous, muscle and surrounding tissue, in which vessels and nerves pass. The muscle layer consists of two layers: the outer longitudinal and the inner circular. The mucosa is covered with a multilayer flat epithelium containing glycogen. The process of glycogen formation is associated with the follicular hormone of the ovary. The vagina is very distensible due to the presence on the front and back walls of two longitudinal ridges, consisting of many transverse folds. There are no glands in the vaginal mucosa. The vaginal secretion is formed by soaking in fluid from the vessels. It has an acidic environment thanks to lactic acid formed from glycogen under the influence of enzymes and waste products of lactobacilli (Dederlein rods). Lactic acid contributes to the death of pathogenic microorganisms.
There are four degrees of purity of vaginal contents.
1st degree: the contents contain only lactobacilli and epithelial cells, the reaction is acidic.
2nd degree: fewer Dederlein rods, single leukocytes, bacteria, many epithelial cells, acidic reaction.
3rd degree: there are few lactobacilli, other types of bacteria predominate, there are many leukocytes, the reaction is slightly alkaline.
4th degree: no lactobacilli, a lot of bacteria and leukocytes, alkaline reaction.
1.2 degrees – a variant of the norm.
3.4 degrees indicate the presence of a pathological process.
The uterus is a smooth muscle hollow organ, pear-shaped, flattened in the anteroposterior direction.
Sections of the uterus: body, isthmus, cervix.
The dome-shaped part of the body above the lines of attachment of the tubes is called bottom of the uterus.
Isthmus- a part of the uterus 1 cm long, located between the body and the cervix. It is separated into a separate section, since the structure of the mucous membrane is similar to the body of the uterus, and the structure of the wall is similar to the cervix. The upper border of the isthmus is the place of dense attachment of the peritoneum to the anterior wall of the uterus. The lower the border is the level of the internal os of the cervical canal.
Neck- the lower part of the uterus, protruding into the vagina. There are two parts: vaginal and supravaginal. The cervix can be either cylindrical or conical (childhood, infantilism). Inside the cervix there is a narrow canal, spindle-shaped, limited internal and external pharynx. The external pharynx opens in the center of the vaginal part of the cervix. It has the shape of a slit in women who have given birth and a round shape in women who have not given birth.
The length of the entire uterus is 8 cm (2/3 of the length is on the body, 1/3 on the cervix), width 4-4.5 cm, wall thickness 1-2 cm. Weight 50-100 g. The uterine cavity has the shape of a triangle.
The wall of the uterus consists of 3 layers: mucous, muscular, serous. The mucous membrane of the uterus (endometrium) covered with a single-layer cylindrical ciliated epithelium containing tubular glands. The uterine mucosa is divided into two layers: superficial (functional), which is released during menstruation, and deep (basal), remaining in place.
Muscle layer (myometrium) richly supplied with vessels, consists of three powerful layers: outer longitudinal; middle circular; inner longitudinal.
Serous lining of the uterus (perimetry) is the peritoneum that covers the body and partly the cervix. From the bladder, the peritoneum passes to the anterior surface of the uterus, forming a vesicouterine cavity between these two organs. From the bottom of the uterus, the peritoneum descends along its posterior surface, lining the supravaginal part of the cervix and the posterior fornix of the vagina , and then passes to the anterior surface of the rectum, thus forming a deep pocket - the rectal-uterine recess (Douglas pouch).
The uterus is located in the center of the small pelvis, inclined anteriorly (anteversio uteri), its bottom is directed to the symphysis, the cervix is posterior, the external cervical os is adjacent to the wall of the posterior vaginal fornix. Between the body and the cervix there is an obtuse angle, open anteriorly (anteflexio uteri).
The fallopian tubes start from the upper corners of the uterus, run along the upper edge of the broad ligament towards the side walls of the pelvis, ending in a funnel. Their length is 10-12 cm. There are three sections in the tube: 1) interstitial- the narrowest part passing through the thickness of the uterus; 2) isthmus (isthmus); 3) ampullary- an expanded part of the tube ending in a funnel with fimbriae. In this section of the tube, fertilization occurs - the fusion of the egg and sperm.
The wall of the pipes consists of three layers: mucous, muscular, serous.
The mucosa is covered with a single-layer cylindrical ciliated epithelium and has longitudinal folding.
The muscle layer consists of three layers: outer - longitudinal; middle - circular; inner - longitudinal.
The peritoneum covers the tube from above and from the sides. Fiber with vessels and nerves is adjacent to the lower section of the tube.
The movement of a fertilized egg through the tube towards the uterus is facilitated by peristaltic contractions of the muscles of the tube, flickering of the cilia of the epithelium directed towards the uterus and longitudinal folding of the mucous membrane of the tube. Along the fold, like a gutter, the egg slides towards the uterus.
OVARIES - paired female gonad, almond-shaped, measuring 3.5-4 x 2-2.5 x 1-1.5 cm, weighing 6-8 g.
The ovary is inserted at one edge into the posterior leaf of the broad ligament (ovarian hilum), the rest of it is not covered by the peritoneum. The ovary is held in a freely suspended state by the broad uterine ligament, the ovarian ligament proper, and the infundibulopelvic ligament.
In the ovary, there is a covering epithelium, a tunica albuginea, a cortical layer with follicles at different stages of development, and a medulla consisting of a connective tissue stroma in which blood vessels and nerves pass.
The ovaries produce sex hormones and eggs mature.
Ligamentous apparatus of the genital organs.
In a normal position, the uterus and appendages are held by the ligamentous apparatus (suspending and securing apparatus) and the pelvic floor muscles (supporting or supporting apparatus).
The hanging apparatus includes:
1. Round uterine ligaments - two cords 10-12 cm long. They extend from the uterine angles, and passing under the wide uterine ligament and through the inguinal canals, they fan out, attaching to the tissue of the pubis and labia majora.
2. The broad ligaments of the uterus are a duplicate of the peritoneum. They run from the ribs of the uterus to the side walls of the pelvis.
3. Uterosacral ligaments - extend from the posterior surface of the uterus in the area of the isthmus, go
posteriorly, covering the rectum on both sides. Attached to the anterior surface of the sacrum.
4. The proper ovarian ligaments run from the fundus of the uterus (posteriorly and below the origin of the tubes) to the ovaries.
5. Infundibulopelvic ligaments are the outermost part of the broad uterine ligament, which passes into the peritoneum of the lateral wall of the pelvis.
The round ligaments keep the uterus in a state of anteversion, the broad ligaments tense when the uterus moves and thereby help keep the uterus in a physiological position, the ovarian ligaments proper and the infundibulopelvic ligaments help keep the uterus in the median position, the uterosacral ligaments pull the uterus posteriorly.
The anchoring apparatus of the uterus consists of connective tissue cords with a small number of muscle cells that extend from the lower part of the uterus: a) anteriorly to the bladder and further to the symphysis; b) to the lateral walls of the pelvis - the main ligaments; c) posteriorly, forming the connective tissue framework of the uterosacral ligaments.
The supporting apparatus consists of the muscles and fascia of the pelvic floor, which prevent the genitals and viscera from descending.
Blood supply to the genital organs.
The external genitalia are supplied with blood by the pudendal artery (a branch of the internal iliac artery).
The blood supply to the internal genital organs is provided by the uterine and ovarian arteries.
The paired uterine artery, departs from the internal iliac artery, goes to the uterus along the periuterine tissue, approaching the lateral surface of the uterus at the level of the internal os, gives off the cervicovaginal branch, supplying blood to the cervix and the upper part of the vagina. The main trunk rises along the rib of the uterus, giving off numerous branches that feed the wall of the uterus, and reaches the bottom of the uterus, where it gives off a branch going to the tube.
The ovarian artery is also paired, departs from the abdominal aorta, descends along with the ureter, passes through the infundibulopelvic ligament, giving branches to the ovary and tube. The terminal sections of the uterine and ovarian arteries anastomose with each other in the upper section of the broad uterine ligament.
Arteries are accompanied by veins of the same name.
Innervation of the genital organs.
The sympathetic and parasympathetic nervous systems (utero-vaginal and ovarian plexuses) take part in the innervation of the genital organs.
The external genitalia and pelvic floor are innervated by the pudendal nerve.
Physiology of female genital organs.
It is known that reproduction, or reproduction, is one of the most important functions
the female body. The reproductive function of women is carried out primarily due to the activity of the ovaries and the uterus, since the egg matures in the ovaries, and in the uterus, under the influence of hormones secreted by the ovaries, changes occur in preparation for the reception of a fertilized egg. The reproductive (childbearing) period continues from 17-18 to 45-50 years.
The childbearing period is preceded by the following stages of a woman’s life: intrauterine; newborns (up to 1 year); childhood (up to 8-10 years); prepubertal and pubertal age (up to 17-18 years). The reproductive period passes into menopause, in which premenopause, menopause (last menstruation) and postmenopause are distinguished.
The menstrual cycle is one of the manifestations of complex biological processes in a woman’s body. The menstrual cycle is characterized by cyclic changes in all parts of the reproductive system, the external manifestation of which is menstruation.
Each normal menstrual cycle is a preparation of a woman’s body for pregnancy. Conception and pregnancy usually occur in the middle of the menstrual cycle after ovulation (rupture of a mature follicle) and the release of an egg ready for fertilization from the ovary. If fertilization does not occur during this period, the unfertilized egg dies, and the prepared one to perceive it, the uterine mucosa is shed and menstrual bleeding begins. Thus, the appearance of menstruation indicates the end of complex cyclic changes in a woman’s body, aimed at preparing for the possible onset of pregnancy.
The first day of menstruation is conventionally taken as the first day of the menstrual cycle, and the duration of the cycle is determined from the beginning of one to the beginning of another (subsequent) menstruation. The normal duration of the menstrual cycle ranges from 21 to 35 days and for most women on average 28 days. Value blood loss on menstrual days is 50-100 ml. The duration of normal menstruation is from 2 to 7 days.
The first menstruation (menarhe) is observed at the age of 10-12 years, but for 1-1.5 years after this, menstruation may be irregular, then a regular menstrual cycle is established.
Regulation of menstrual function is carried out through a complex neurohumoral pathway with the participation of five links (levels): 1) cerebral cortex; 2) hypothalamus; 3) pituitary gland; 4) ovaries; 5) peripheral organs called target organs (fallopian tubes, uterus and vagina). Target organs, due to the presence of special hormonal receptors, most clearly respond to the action of sex hormones produced in the ovaries during the menstrual cycle.
The cyclic functional changes that occur in a woman’s body are conventionally combined into several groups. These are changes in the hypothalamic-pituitary system, the ovaries (ovarian cycle), the uterus and, first of all, in its mucous membrane (uterine cycle). Along with this, cyclic shifts occur in throughout a woman’s body, known as the menstrual wave. They are expressed in periodic changes in the activity of the central nervous system, metabolic processes, the function of the cardiovascular system, thermoregulation, etc.
The cerebral cortex exerts a regulating and corrective influence on processes associated with the development of menstrual function. Through the cerebral cortex, the external environment influences the underlying parts of the nervous system involved in the regulation of the menstrual cycle.
The hypothalamus is a section of the diencephalon and, through a number of nerve conductors (axons), is connected to various parts of the brain, due to which the central regulation of its activity is carried out. In addition, the hypothalamus contains receptors for all peripheral hormones, including ovarian (estrogens and progesterone). Thus, complex interactions take place in the hypothalamus between impulses entering the body from the environment through the central nervous system, on the one hand, and
influences of hormones of peripheral endocrine glands - on the other.
Under the control of the hypothalamus is the activity of the brain appendage - the pituitary gland, in the anterior lobe of which gonadotropic hormones are secreted, which affect the function of the ovaries.
The controlling effect of the hypothalamus on the anterior pituitary gland is carried out through the secretion of neurohormones.
Neurohormones that stimulate the release of tropic hormones from the pituitary gland are called releasing factors or liberins. Along with this, there are also neurohormones that inhibit the release of tropic neurohormones, called statins.
The anterior lobe of the pituitary gland secretes follicle-stimulating (FSH) and luteinizing (LT) gonadotropins, as well as prolactin.
FSH stimulates the development and maturation of the follicle in one of the ovaries. Under the combined influence of FSH and LH, the mature follicle ruptures, or ovulation. After ovulation, under the predominant influence of LH, the corpus luteum is formed from the elements of the follicle (the connective tissue membrane and the granulosa cells lining its inner surface). Prolactin promotes the production of the hormone progesterone by the corpus luteum.
In the ovaries, during the menstrual cycle, follicles grow and the egg matures, which eventually becomes ready for fertilization. At the same time, the ovaries produce sex hormones that ensure changes in the uterine mucosa, which is capable of receiving a fertilized egg.
Sex hormones synthesized by the ovaries affect target tissues and organs by interacting with the corresponding receptors. Target tissues and organs include the genitals, primarily the uterus, mammary glands, spongy bones, brain, endothelium and smooth muscle cells blood vessels, myocardium, skin and its appendages (hair follicles and sebaceous glands), etc.
Estrogen hormones contribute to the formation of genital organs and the development of secondary sexual characteristics during puberty. Androgens influence the appearance of pubic and axillary hair. Progesterone controls the secretory phase of the menstrual cycle and prepares the endometrium for implantation. Sex hormones play an important role in the development of pregnancy and childbirth
Cyclic changes in the ovaries include three main processes:
1) growth of follicles and formation of a dominant follicle (follicular phase);
2) ovulation;
3) formation, development and regression of the corpus luteum (luteal phase).
At the birth of a girl, there are 2 million follicles in the ovary, 99% of which undergo atresia throughout life. The process of atresia refers to the reverse development of follicles at one of the stages of its development. By the time of menarche, the ovary contains about 200-400 thousand follicles, of which mature to the ovulation stage of 300-400.
It is customary to distinguish the following main stages of follicle development: primordial follicle, preantral follicle, antral follicle, preovulatory (dominant) follicle. The dominant follicle is the largest (21 mm at the time of ovulation).
Ovulation is the rupture of the dominant follicle and the release of an egg. Thinning and rupture of the follicle wall occurs mainly under the influence of the enzyme collagenase.
After the release of the egg into the cavity of the follicle, the resulting capillaries quickly grow. Granulosa cells undergo luteinization: the volume of the cytoplasm increases in them and lipid inclusions are formed. LH, interacting with the protein receptors of granulosa cells, stimulates the process of their luteinization. This process leads to the formation of the corpus luteum.
The corpus luteum is a transient endocrine gland that functions for 14 days, regardless of the duration of the menstrual cycle. In the absence of pregnancy, the corpus luteum regresses.
The cyclic secretion of hormones in the ovary determines changes in the uterine mucosa. The endometrium consists of two layers: the basal layer, which is not shed during menstruation, and the functional layer, which undergoes cyclic changes during the menstrual cycle and is shed during menstruation.
The following phases of endometrial change during the cycle are distinguished:
1) proliferation phase; 3) menstruation;
2) secretion phase; 4) regeneration phase
Proliferation phase. As the secretion of estradiol by the growing ovarian follicles increases, the endometrium undergoes proliferative changes. The cells of the basal layer actively multiply. A new superficial loose layer with elongated tubular glands is formed. This layer quickly thickens 4-5 times. The tubular glands lined with cylindrical epithelium elongate.
Secretion phase. In the luteal phase of the ovarian cycle, under the influence of progesterone, the tortuosity of the glands increases, and their lumen gradually expands. The cells of the stroma, increasing in volume, come closer to each other. The secretion of the glands intensifies. They acquire a sawtooth shape. Increased vascularization of the stroma is noted.
Menstruation. This is the rejection of the functional layer of the endometrium. The endocrine basis for the onset of menstruation is a pronounced decrease in the levels of progesterone and estradiol due to regression of the corpus luteum.
Regeneration phase. Regeneration of the endometrium is observed from the very beginning of menstruation. By the end of the 24th hour of menstruation, 2/3 of the functional layer of the endometrium is rejected. The basal layer contains epithelial cells of the stroma, which are the basis for endometrial regeneration, which is usually completely completed by the 5th day of the cycle. In parallel, angiogenesis is completed with restoration of the integrity of ruptured arterioles, veins and capillaries.
In the regulation of menstrual function, the implementation of the principle of the so-called feedback between the hypothalamus, the anterior lobe of the pituitary gland and the ovaries is of great importance. It is customary to consider two types of feedback: negative and positive.
With a negative type of feedback, the production of central neurohormones (releasing factors) and gonadotropins of the adenohypophysis is suppressed by ovarian hormones produced in large quantities. With a positive type of feedback, the production of releasing factors in the hypothalamus and gonadotropins in the pituitary gland is stimulated by low levels of ovarian hormones in the blood. The implementation of the principle of negative and positive feedback underlies the self-regulation of the function of the hypothalamic-pituitary-ovarian system.
Female pelvis and pelvic floor.
The bony pelvis is of great importance in obstetrics. It is a container for the internal genital organs, rectum, bladder and surrounding tissues, and during childbirth it forms the birth canal through which the fetus moves.
The pelvis consists of four bones: two pelvic (nameless), sacrum and coccyx.
The pelvic bone consists of three bones: the ilium, the pubis and the ischium, connected to each other in the area of the acetabulum.
There are two sections of the pelvis: large pelvis and small pelvis. The border between them runs anteriorly along the upper edge of the symphysis pubis, laterally along the innominate line, and posteriorly along the sacral promontory.
Big pelvis limited laterally by the wings of the ilium, posteriorly by the last lumbar vertebrae. In front it does not have a bony wall. Based on the size of the large pelvis, which is fairly easy to measure, one can judge the shape and size of the small pelvis.
Small pelvis is the bony part of the birth canal. The shape and size of the pelvis are of great importance during labor. With sharp degrees of narrowing of the pelvis and its deformations, childbirth through the natural birth canal becomes impossible, and the woman is delivered by cesarean section.
The posterior wall of the pelvis consists of the sacrum and coccyx, the lateral ones are formed by the ischial bones, and the anterior wall is formed by the pubic bones and the symphysis. The posterior wall of the pelvis is three times longer than the anterior one.
In the small pelvis there are the following sections: inlet, cavity and outlet. In the pelvic cavity there are a wide and a narrow part. In accordance with this, four planes of the small pelvis are considered: 1) the plane of the entrance to the small pelvis; 2) the plane of the wide part of the small pelvis; 3) the plane of the narrow part of the small pelvis; 4) the plane of the exit of the pelvis.
The plane of entry into the pelvis has the following boundaries: in front – the upper edge of the symphysis and pubic bones, on the sides – innominate lines, in the back – the sacral promontory. The entrance plane is kidney-shaped. In the entrance plane, the following dimensions are distinguished: straight, which is the true conjugate of the small pelvis (11 cm), transverse (13 cm) and two oblique (12 cm).
The plane of the wide part of the pelvic cavity limited in front by the middle of the inner surface of the symphysis, on the sides by the middle of the acetabulum, and behind by the junction of the II and III sacral vertebrae. In the wide part there are two sizes, straight (12.5 cm) and transverse (12.5 cm)
The plane of the narrow part of the pelvic cavity bounded in front by the lower edge of the symphysis, on the sides by the spines of the ischial bones, and behind by the sacrococcygeal joint. There are also two sizes: straight (11 cm) and transverse (10.5 cm).
Pelvic exit plane has the following boundaries: in front - the lower edge of the symphysis, on the sides - the ischial tuberosities, in the back - the coccyx. The exit plane of the pelvis consists of two triangular planes, the common base of which is the line connecting the ischial tuberosities. The direct size of the pelvic outlet is from the apex of the coccyx to the lower edge of the symphysis; due to the mobility of the coccyx during the passage of the fetus through the small pelvis, it increases by 1.5 - 2 cm (9.5-11.5 cm). The transverse size is 11 cm.
The line connecting the midpoints of the direct dimensions of all planes of the pelvis is called wired pelvic axis, since it is along this line that the fetus passes through the birth canal during childbirth. The wire axis is curved according to the concavity of the sacrum.
The intersection of the plane of the entrance to the pelvis with the horizon plane forms pelvic inclination angle equal to 50-55’.
Differences in the structure of the female and male pelvis begin to appear during puberty and become pronounced in adulthood. The bones of the female pelvis are thinner, smoother and less massive than the bones of the male pelvis. The plane of entrance to the pelvis in women has a transverse oval shape, while in men it has the shape of a card heart (due to the strong protrusion of the promontory).
Anatomically, the female pelvis is lower, wider and larger in volume. The pubic symphysis in the female pelvis is shorter than the male one. The sacrum in women is wider, the sacral cavity is moderately concave. The pelvic cavity in women is closer to a cylinder in outline, and in men it narrows funnel-shaped downwards. The pubic angle is wider (90-100’) than in men (70-75’). The tailbone protrudes anteriorly less than in the male pelvis. The ischial bones in the female pelvis are parallel to each other, and in the male pelvis they converge.
All of these features are very important in the process of birth.
Pelvic floor muscles.
The outlet of the pelvis is closed from below by a powerful muscular-fascial layer, which is called pelvic floor.
Two diaphragms take part in the formation of the pelvic floor - the pelvic and genitourinary.
Pelvic diaphragm occupies the back of the perineum and has the shape of a triangle, the apex of which faces the coccyx, and the corners face the ischial tuberosities.
Superficial layer of the muscles of the pelvic diaphragm represented by an unpaired muscle - the external sphincter of the anus (m.sphincter ani externus). The deep bundles of this muscle start from the apex of the coccyx, wrap around the anus and end in the tendon center of the perineum.
To the deep muscles of the pelvic diaphragm There are two muscles: the levator ani muscle (m.levator ani) and the coccygeus muscle (m. coccygeus).
The levator ani muscle is a paired, triangular-shaped muscle that forms a funnel with a similar muscle on the other side, the wide part facing upward and attached to the inner surface of the pelvic walls. The lower parts of both muscles, tapering, cover the rectum in the form of a loop. This muscle consists of the pubococcygeus (m. pubococcygeus) and iliococcygeus muscles (m.iliococcygeus).
The coccygeus muscle in the form of a triangular plate is located on the inner surface of the sacrospinous ligament. With a narrow apex it starts from the ischial spine, and with a wide base it is attached to the lateral edges of the lower sacral and coccygeal vertebrae.
Urogenital diaphragm–fascial – muscular plate located in the anterior part of the pelvic floor between the lower branches of the pubic and ischial bones.
The muscles of the urogenital diaphragm are divided into superficial and deep.
To the superficial include the superficial transverse perineal muscle, the ischiocavernosus muscle and the bulbospongiosus muscle.
The superficial transverse muscle of the perineum (m.transversus perinei superficialis) is paired, unstable, and can sometimes be absent on one or both sides. This muscle is a thin muscular plate located at the posterior edge of the urogenital diaphragm and running across the perineum. Its lateral end is attached to the ischium, and its medial part crosses along the midline with the muscle of the same name on the opposite side, partly intertwining with the bulbospongiosus muscle, partly with the external muscle that compresses the anus.
The ischiocavernosus muscle (m.ischiocavernosus) is a steam muscle that looks like a narrow muscle strip. It begins as a narrow tendon from the inner surface of the ischial tuberosity, bypasses the stalk of the clitoris and is woven into its tunica albuginea.
The bulbospongiosus muscle (m. bulbospongiosus) is a steam muscle, surrounds the entrance to the vagina, and has the shape of an elongated oval. This muscle starts from the tendinous center of the perineum and the external sphincter of the anus and is attached to the dorsal surface of the clitoris, intertwined with its tunica albuginea.
To the deep The muscles of the genitourinary diaphragm include the deep transverse perineal muscle and the urethral sphincter.
The deep transverse muscle of the perineum (m. transversus perinei profundus) is a paired, narrow muscle starting from the ischial tuberosities. It goes to the midline, where it connects with the muscle of the same name on the opposite side, participating in the formation of the tendon center of the perineum.
The sphincter of the urethra (m.sphincter urethrae) is a paired muscle that lies anterior to the previous one. Peripherally located bundles of this muscle are directed to the branches of the pubic bones and to the fascia of the genitourinary diaphragm. Bundles of this muscle surround the urethra. This muscle connects to the vagina.
The female genital organs are divided into external (vulva) and internal. The internal genital organs ensure conception, the external genital organs are involved in sexual intercourse and are responsible for sexual sensations.
The internal genital organs include the vagina, uterus, fallopian tubes and ovaries. To the external - the pubis, labia majora and minora, clitoris, vestibule of the vagina, large glands of the vestibule of the vagina (Bartholin's glands). The boundary between the external and internal genital organs is the hymen, and after the onset of sexual activity - its remains.
External genitalia
Pubis(venus tubercle, lunar mound) - the lowest part of a woman’s anterior abdominal wall, slightly elevated due to a well-developed subcutaneous fat layer. The pubic area has a pronounced hairline, which is usually darker than on the head, and in appearance is a triangle with a sharply defined upper horizontal border and a downward-pointing apex. The labia (labia pudendum) are folds of skin located on both sides of the genital slit and the vestibule of the vagina. Distinguish between labia majora and labia minora
Labia majora - folds of skin, in the thickness of which there is fat-rich fiber. The skin of the labia majora has many sebaceous and sweat glands and during puberty the outside is covered with hair. The Bartholin glands are located in the lower parts of the labia majora. In the absence of sexual stimulation, the labia majora are usually closed at the midline, providing mechanical protection for the urethra and vaginal opening.
Labia minora located between the labia majora in the form of two thin, delicate pink folds of skin that limit the vestibule of the vagina. They have a large number of sebaceous glands, blood vessels and nerve endings, which allows them to be considered a sexual sense organ. The labia minora meet over the clitoris to form a fold of skin called the clitoral foreskin. During sexual arousal, the labia minora become saturated with blood and turn into elastic ridges, narrowing the entrance to the vagina, which increases the intensity of sexual sensations when the penis is inserted.
Clitoris- the female external genital organ located at the upper ends of the labia minora. This is a unique organ whose sole function is to concentrate and accumulate sexual sensations. The size and appearance of the clitoris vary from person to person. The length is about 4-5 mm, but in some women it reaches 1 cm or more. When sexually aroused, the clitoris increases in size.
The vestibule of the vagina - a slit-like space limited on the sides by the labia minora, in front by the clitoris, and behind by the posterior commissure of the labia. From above, the vestibule of the vagina is covered with the hymen or its remains. At the vestibule of the vagina, the external opening of the urethra opens, located between the clitoris and the entrance to the vagina. The vestibule of the vagina is sensitive to touch and at the moment of sexual arousal it is filled with blood, forming an elastic elastic “cuff”, which is moistened by the secretion of the large and small glands (vaginal lubrication) and opens the entrance to the vagina.
Bartholin's glands(large glands of the vestibule of the vagina) are located in the thickness of the labia majora at their base. The size of one gland is about 1.5-2 cm. During sexual arousal and intercourse, the glands secrete a viscous grayish protein-rich liquid (vaginal fluid, lubricant).
Internal genital organs
Vagina (vagina)- the internal genital organ of a woman, which is involved in the process of sexual intercourse, and during childbirth is part of the birth canal. The length of the vagina in women is, on average, 8 cm. But in some it can be longer (up to 10-12 cm) or shorter (up to 6 cm). The inside of the vagina is lined with a mucous membrane with a large number of folds, which allows it to stretch during childbirth.
Ovaries- female gonads, from the moment of birth they contain more than a million immature eggs. The ovaries also produce the hormones estrogen and progesterone. Due to the constant cyclical changes in the content of these hormones in the body, as well as the release of hormones by the pituitary gland, the maturation of eggs and their subsequent release from the ovaries occur. This process is repeated approximately every 28 days. The release of the egg is called ovulation. In close proximity to each ovary is a fallopian tube.
Fallopian tubes (fallopian tubes) - two hollow tubes with holes running from the ovaries to the uterus and opening at the top of the uterus. There are villi at the ends of the tubes near the ovaries. When the egg leaves the ovary, the villi, with their continuous movements, try to capture it and drive it into the tube so that it can continue its journey to the uterus.
Uterus- a hollow organ shaped like a pear. It is located in the pelvic cavity. During pregnancy, the uterus enlarges as the fetus grows. The walls of the uterus are made up of layers of muscle. With the onset of contractions and during childbirth, the muscles of the uterus contract, the cervix stretches and dilates, and the fetus is pushed into the birth canal.
Cervix represents its lower part with a passage connecting the uterine cavity and vagina. During childbirth, the walls of the cervix become thinner, the os of the cervix expands and takes the form of a round hole with a diameter of approximately 10 centimeters, due to this it becomes possible for the fetus to exit the uterus into the vagina.
Hymen(hymen) - a thin fold of the mucous membrane in virgins, located at the entrance to the vagina between the internal and external genitalia. Each girl has individual, unique features of the hymen. The hymen has one or more holes of various sizes and shapes through which blood is released during menstruation.
During the first sexual intercourse, the hymen ruptures (defloration), usually with the release of a small amount of blood, sometimes with a feeling of pain. At the age of over 22 years, the hymen is less elastic than at a young age, so in young girls defloration usually occurs more easily and with less blood loss; there are often cases of sexual intercourse without hymen rupture. Hymen tears can be deep, with heavy bleeding, or superficial, with minor bleeding. Sometimes, if the hymen is too elastic, ruptures do not occur; in this case, defloration occurs without pain and bleeding. After childbirth, the hymen is completely destroyed, leaving only individual flaps.
The lack of blood in a girl during defloration should not cause jealousy or suspicion, since it is necessary to take into account the individual structural features of the female genital organs.
In order to reduce pain during defloration and increase the duration of sexual intercourse, you can use lubricants containing drugs that reduce the pain sensitivity of the vaginal mucosa.
