Anatomy and physiology of the uterus. Menstrual cycle. Lecture: menstrual cycle. regulation of the menstrual cycle
Menstruation (from menstruus - monthly) - cyclical short-term uterine bleeding- reflects the failure of a complex integrated system designed to ensure conception and development of pregnancy in the early stages. This system includes higher brain centers, the hypothalamus, pituitary gland, ovaries, uterus and target organs, functionally interconnected. The complex of complex biological processes occurring in the period between menstruation is called the menstrual cycle, the duration of which is usually counted from the first day of the previous to the first day of subsequent bleeding. Duration menstrual cycle normally ranges from 21 to 36 days, the most common is a 28-day menstrual cycle; the duration of menstrual bleeding varies from 3 to 7 days, the volume of blood loss does not exceed 100 ml.
Cortex
Regulation of the normal menstrual cycle occurs at the level of specialized neurons of the brain, which receive information about the state of the external environment and convert it into neurohormonal signals. The latter, in turn, enter the neurosecretory cells of the hypothalamus through the system of neurotransmitters (nerve impulse transmitters). The function of neurotransmitters is performed by biogenic amines-catecholamines - dopamine and norepinephrine, indoles - serotonin, as well as neuropeptides of morphine-like origin, opioid peptides - endorphins and enkephalins.
Dopamine, norepinephrine and serotonin control hypothalamic neurons that secrete gonadotropin-releasing factor (GTRF): dopamine supports the secretion of GTRF in the arcuate nuclei, and also inhibits the release of prolactin by the adenopituitary gland; norepinephrine regulates the transmission of impulses to the preoptic nuclei of the hypothalamus and stimulates the ovulatory release of GTRF; serotonin controls the cyclic secretion of GTRF from neurons of the anterior (visual) hypothalamus. Opioid peptides suppress the secretion of luteinizing hormone, inhibit the stimulating effect of dopamine, and their antagonist, nalaxone, causes a sharp increase in the level of GTRF.
Hypothalamus
The nuclei of the hypophysiotropic zone of the hypothalamus (supraoptic, paraventricular, arcuate and ventromedial) produce specific neurosecrets with diametrically opposite pharmacological effects: liberins, or releasing factors, releasing the corresponding triple hormones in the anterior pituitary gland and statins, inhibiting their release.
Currently, seven liberins are known - corticoliberin (adrenocorticotropic releasing factor, ACTH-RF), somatotropic liberin (somatotropic STH-RF), thyreoliberin (thyroid-tropic releasing factor, T-RF), melanoliberin (melanotropic releasing factor, M-RF) , folliberin (follicle-stimulating releasing factor, FSH-RF), luliberin (luteinizing releasing factor, LH-RF), prolactoliberin (prolactin releasing factor, PRF) and three statins - melanostatin (melanotropic inhibitory factor, M-IF), somatostatin (somatotropic inhibitory factor, S-IF), prolactostatin (prolactin inhibitory factor, PIF).
Luteinizing releasing factor has been isolated, synthesized and described in detail. However, the chemical nature of folliberin and its analogues has not yet been studied. However, it has been proven that luliberin has the ability to stimulate the secretion of both hormones of the adenohypophysis - both follicle-stimulating and luteinizing hormones. Therefore, the generally accepted term for these liberins is gonadotropin-releasing factor (GTRF).
In addition to hypophysiotropic hormones, the supraoptic and paraventricular nuclei of the hypothalamus synthesize two hormones - vasopressin (antidiuretic hormone, ADH) and oxytocin, which are deposited in the neurohypophysis.
Pituitary
Basophilic cells of the adenohypophysis - gonadotropocytes - secrete hormones - gonadotropins, which are directly involved in the regulation of the menstrual cycle. Gonadotropic hormones include follitropin, or follicle-stimulating hormone (FSH) and lutropin, or luteinizing hormone (FSH). Lutropin and follitropin are glycoproteins consisting of two peptide chains - a- and b-subunits; The a-chains of gonadotropins are identical, while the difference in the b-links determines their biological specificity.
FSH stimulates the growth and maturation of follicles, proliferation of granulosa cells, and also induces the formation of LH receptors on the surface of these cells. Under the influence of FSH, the level of aromatase in the ripening follicle increases. Lutropin affects the synthesis of androgens (estrogen precursors) in theca cells, in combination with FSH ensures ovulation and stimulates the synthesis of progesterone in the luteinized granulosa cells of the ovulated follicle. Currently, two types of gonadotropin secretion have been discovered - tonic and cyclic. Tonic release of gonadotropins promotes the development of follicles and their production of estrogens; cyclical - ensures a change in phases of low and high secretion of hormones and, in particular, their pre-ovulatory peak.
A group of acidophilic cells of the anterior pituitary gland - lactotropocytes - produces prolactin (PRL). Prolactin is formed by a single peptide chain, its biological effects are diverse:
1) PRL stimulates the growth of mammary glands and regulates lactation;
2) has a fat-mobilizing and hypotensive effect;
3) in increased quantities it has an inhibitory effect on the growth and maturation of the follicle.
Other hormones of the adenohypophysis (thyrotropin, corticotropin, somatotropin, melanotropin) play a minor role in human generative processes.
The posterior lobe of the pituitary gland, the neurohypophysis, as mentioned above, is not an endocrine gland, but only deposits the hormones of the hypothalamus - vasopressin and oxytocin, which are found in the body in the form of a protein complex (Van Dyck protein).
Ovaries
The generative function of the ovaries is characterized by cyclic maturation of the follicle, ovulation, release of an egg capable of conception, and provision of secretory transformations in the endometrium aimed at the reception of a fertilized egg.
The main morphofunctional unit of the ovaries is the follicle. In accordance with the International Histological Classification (1994), 4 types of follicles are distinguished: primordial, primary, secondary (antral, cavitary, vesicular), mature (preovulatory, graafian).
Primordial follicles form in the fifth month intrauterine development fetus and exist for several years after the permanent cessation of menstruation. By the time of birth, both ovaries contain about 300,000-500,000 primordial follicles; subsequently, their number sharply decreases and by the age of 40 it is about 40,000-50,000 (physiological atresia of primordial follicles). The primordial follicle consists of an egg surrounded by a single row of follicular epithelium; its diameter does not exceed 50 microns (Fig. 1).
Rice. 1. Anatomy of the ovary
The stage of the primary follicle is characterized by increased proliferation of the follicular epithelium, the cells of which acquire a granular structure and form a granular layer (stratum granulosum). The cells of this layer secrete a secretion (liquor folliculi), which accumulates in the intercellular space. The size of the egg gradually increases to 55-90 microns in diameter. The resulting fluid pushes the egg to the periphery, where the cells of the granular layer surround it on all sides and form the egg-bearing tubercle (cumulus oophorus). Another part of these cells moves to the periphery of the follicle and forms a thin-layer granular (granulosa) membrane (membrana granulosus).
During the formation of the secondary follicle, its walls are stretched by the liquid: the oocyte in this follicle no longer increases (to at this moment its diameter is 100-180 microns), but the diameter of the follicle itself increases and reaches 10-20 mm. The shell of the secondary follicle is clearly differentiated into outer and inner. The inner shell (theca interna) consists of 2-4 layers of cells located on a granular membrane. Outer shell(theca externa), is localized directly on the internal and is represented by a differentiated connective tissue stroma.
In a mature follicle, the egg, enclosed in the egg-bearing tubercle, is covered with a transparent (vitreous) membrane (zona pellucida), on which granular cells are located in the radial direction and form a radiant crown (corona radiata) (Fig. 2).
Rice. 5. Follicle development
Ovulation is the rupture of a mature follicle with the release of an egg, surrounded by the corona radiata, into the abdominal cavity, and subsequently into the ampulla of the fallopian tube. Violation of the integrity of the follicle occurs in its thinnest and most convex part, called the stigma (stigma folliculi).
The maturation of the follicle occurs periodically, after a certain interval of time. In primates and humans, one follicle matures during the menstrual cycle, the rest undergo reverse development and turn into fibrous and atretic bodies. During the entire reproductive period, about 400 eggs ovulate; the remaining oocytes undergo atresia. The viability of the egg is within 12-24 hours.
Luteinization represents specific transformations of the follicle in the postovulatory period. As a result of luteinization (coloring yellow due to the accumulation of lipochromic pigment - lutein), reproduction and proliferation of cells of the granular membrane of the ovulated follicle, a formation called the corpus luteum (corpus luteum) is formed (cells of the internal zone, transforming into theca cells, also undergo luteinization). In cases where fertilization does not occur, the corpus luteum exists for 12-14 days and undergoes next stages development:
a) the proliferation stage is characterized by the proliferation of granulosa cells and hyperemia of the internal zone;
b) the vascularization stage is distinguished by the appearance of a rich vascular network, the vessels of which are directed from the internal zone to the center of the corpus luteum; multiplying granulosa cells turn into polygonal ones, in the protoplasm of which lutein accumulates;
c) blossoming stage - the period of maximum development, the luteal layer acquires folding specific to the corpus luteum;
d) stage of reverse development - degenerative transformation of luteal cells is observed, the corpus luteum becomes discolored, fibrosed and hyalinized, its size continuously decreases; subsequently, after 1-2 months, a white body(corpus albicans), which then completely resolves.
Thus, the ovarian cycle consists of two phases - follicular and luteal. The follicular phase begins after menstruation and ends with ovulation; The luteal phase occupies the period between ovulation and the onset of menstruation.
Hormonal function of the ovaries
During their existence, the cells of the granulosa membrane, the inner shell of the follicle and the corpus luteum perform the function of an endocrine gland and synthesize three main types of steroid hormones - estrogens, gestagens, and androgens.
Estrogens secreted by cells of the granular membrane, inner membrane and, to a lesser extent, interstitial cells. Estrogens are produced in small quantities in the corpus luteum, cortical layer adrenal glands, in pregnant women - in the placenta (syncytial cells of chorionic villi). The main estrogens of the ovary are estradiol, estrone and estriol (the first two hormones are predominantly synthesized).
The activity of 0.1 mg of estrone is conventionally taken as 1 IU of estrogenic activity. According to the Allen and Doisy test ( least amount drug that causes estrus in castrated mice), estradiol has the greatest activity, followed by estrone and estriol (ratio 1: 7: 100).
Estrogen metabolism
Estrogens circulate in the blood in free and protein-bound (biologically inactive) forms. The main amount of estrogens is in the blood plasma (up to 70%), 30% - in shaped elements. From the blood, estrogens enter the liver, then into the bile and intestines, from where they are partially reabsorbed into the blood and penetrate into the liver (enterohepatic circulation), and partially excreted in the feces. In the liver, estrogens are inactivated by forming paired compounds with sulfuric and glucuronic acids, which enter the kidneys and are excreted in the urine.
The effects of steroid hormones on the body are systematized as follows.
Vegetative effects(strictly specific) - estrogens have a specific effect on the female genital organs: they stimulate the development of secondary sexual characteristics, cause hyperplasia and hypertrophy of the endometrium and myometrium, improve blood supply to the uterus, and promote the development of the excretory system of the mammary glands.
Generative impact(less specific) - estrogens stimulate trophic processes during follicle maturation, promote the formation and growth of granulosa, egg formation and development of the corpus luteum; prepare the ovary for the effects of gonadotropic hormones.
Overall Impact(nonspecific) - estrogens in physiological quantity stimulate the reticuloendothelial system (increase the production of antibodies and the activity of phagocytes, increasing the body’s resistance to infections), delay soft tissues nitrogen, sodium, liquid, in bones - calcium, phosphorus. Cause an increase in the concentration of glycogen, glucose, phosphorus, creatinine, iron and copper in the blood and muscles; reduce the content of cholesterol, phospholipids and total fat in the liver and blood, accelerate the synthesis of higher fatty acids.
Gestagens secreted by luteal cells of the corpus luteum, luteinizing granulosa cells and follicular membranes (the main source outside pregnancy), as well as the adrenal cortex and placenta. The main gestagen of the ovaries is progesterone; in addition to progesterone, the ovaries synthesize 17a-hydroxyprogesterone, D4-pregnenol-20a-one-3, D4-pregnenol-20b-one-3.
Metabolism gestagens proceeds according to the following scheme: progesterone-allopregnanolone-pregnanolone-pregnanediol. The last two metabolites do not have biological activity: binding in the liver with glucuronic and sulfuric acids, they are excreted in the urine.
Vegetative effects- gestagens have an effect on the genitals after preliminary estrogen stimulation: they suppress the proliferation of the endometrium caused by estrogens, and carry out secretory transformations in the endometrium; When an egg is fertilized, gestagens suppress ovulation, prevent uterine contractions (“protector” of pregnancy), and promote the development of alveoli in the mammary glands.
Generative impact- gestagens in small doses stimulate the secretion of FSH, in large doses they block both FSH and LH; cause excitation of the thermoregulatory center located in the hypothalamus, which is manifested by an increase in basal temperature.
Overall Impact- gestagens in physiological conditions reduce the content of amine nitrogen in the blood plasma, increase the excretion of amino acids, increase the secretion of gastric juice, and inhibit the secretion of bile.
Androgens secreted by the cells of the inner lining of the follicle, interstitial cells (in small quantities) and in the reticular zone of the adrenal cortex (the main source). The main androgens of the ovaries are androstenedione and dshydroepiandrosterone; testosterone and epitestosterone are synthesized in small doses.
The specific effect of androgens on the reproductive system depends on the level of their secretion (small doses stimulate the function of the pituitary gland, large doses block it) and can manifest itself in the form of the following effects:
- virile effect - large doses of androgens cause clitoral hypertrophy, male-type hair growth, growth of the cricoid cartilage, and the appearance of acne vulgaris;
- gonadotropic effect - small doses of androgens stimulate the secretion of gonadotropic hormones, promote follicle growth and maturation, ovulation, luteinization;
- antigonadotropic effect - a high level of androgen concentration in the preovulatory period suppresses ovulation and subsequently causes follicular atresia;
- estrogenic effect - in small doses androgens cause proliferation of the endometrium and vaginal epithelium;
- antiestrogenic effect - large doses of androgens block proliferation processes in the endometrium and lead to the disappearance of acidophilic cells in the vaginal smear.
Overall Impact
Androgens have pronounced anabolic activity and enhance protein synthesis by tissues; retain nitrogen, sodium and chlorine in the body, reduce the excretion of urea. Accelerate bone growth and ossification of epiphyseal cartilage, increase the number of red blood cells and hemoglobin.
Other ovarian hormones: inhibin, synthesized by granular cells, has an inhibitory effect on the synthesis of FSH; oxytocin (found in follicular fluid, corpus luteum) - in the ovaries it has a luteolytic effect, promotes regression of the corpus luteum; relaxin, formed in granulosa cells and the corpus luteum, promotes ovulation, relaxes the myometrium.
Uterus
Under the influence of ovarian hormones, cyclic changes are observed in the myometrium and endometrium, corresponding to the follicular and luteal phases in the ovaries. The follicular phase is characterized by hypertrophy of the cells of the muscular layer of the uterus, and the luteal phase is characterized by their hyperplasia. Functional changes in the endometrium are reflected by a sequential change in the stages of proliferation, secretion, desquamation (menstruation), and regeneration.
The proliferation phase (corresponding to the follicular phase) is characterized by transformations that occur under the influence of estrogens.
Early stage of proliferation (before 7-8 days of the menstrual cycle): the surface of the mucous membrane is lined with flattened cylindrical epithelium, the glands look like straight or slightly convoluted short tubes with a narrow lumen, the epithelium of the glands is single-row low cylindrical; the stroma consists of spindle-shaped or stellate reticular cells with delicate processes; in the cells of the stroma and epithelium there are single mitoses.
Middle stage of proliferation (up to 10-12 days of the menstrual cycle): the surface of the mucous membrane is lined with high prismatic epithelium, the glands lengthen, become more tortuous, the stroma is swollen, loosened; the number of mitoses increases.
Late stage of proliferation (before ovulation): the glands become sharply tortuous, sometimes spur-shaped, their lumen expands, the epithelium lining the glands is multirowed, the stroma is juicy, spiral arteries reach the surface of the endometrium, and are moderately tortuous.
Secretion phase(corresponds to the luteal phase) reflects changes due to the effects of progesterone.
The early stage of secretion (before the 18th day of the menstrual cycle) is characterized by further development glands and expansion of their lumen, the most characteristic sign of this stage is the appearance of subnuclear vacuoles containing glycogen in the epithelium; there are no mitoses in the epithelium of the glands at the end of the stage; the stroma is juicy and loose.
The middle stage of secretion (19-23 days of the menstrual cycle) - reflects the transformations characteristic of the heyday of the corpus luteum, i.e., the period of maximum gestagenic saturation. The functional layer becomes higher, clearly divided into deep and superficial layers: deep - spongy, spongy, superficial - compact. The glands expand, their walls become folded; in the lumen of the glands a secret appears containing glycogen and acidic mucopolysaccharides. Stroma with symptoms of perivascular decidual reaction. The spiral arteries are sharply tortuous and form “tangles” (the most reliable sign that determines the luteinizing effect). Structure and functional state endometrium on days 20-22 of the 28-day menstrual cycle represent optimal conditions for blastocyst implantation.
Late stage of secretion (24-27 days of the menstrual cycle): during this period, processes associated with regression of the corpus luteum and, consequently, a decrease in the concentration of hormones produced by it are observed - the trophism of the endometrium is disrupted, its degenerative changes are formed, morphologically the endometrium regresses, signs of its ischemia appear . At the same time, the juiciness of the tissue decreases, which leads to wrinkling of the stroma of the functional layer. The folding of the walls of the glands intensifies. On the 26-27th day of the menstrual cycle, lacunar expansion of capillaries and focal hemorrhages into the stroma are observed in the superficial layers of the compact layer; due to the melting of the fibrous structures, areas of separation of the cells of the stroma and the epithelium of the glands appear. This state of the endometrium is called “anatomical menstruation” and immediately precedes clinical menstruation.
Bleeding phase, desquamation(28-2 day of the menstrual cycle). In the mechanism of menstrual bleeding, leading importance is given to circulatory disorders caused by prolonged spasm of the arteries (stasis, blood clots, fragility and permeability of the vascular wall, hemorrhage into the stroma, leukocyte infiltration). The result of these transformations is necrobiosis of the tissue and its melting. Due to the dilation of blood vessels that occurs after a long spasm, a large amount of blood enters the endometrial tissue, which leads to rupture of blood vessels and rejection - desquamation - of necrotic sections of the functional layer of the endometrium, i.e. to menstrual bleeding.
Regeneration phase(3-4 days of the menstrual cycle) is short, characterized by regeneration of the endometrium from the cells of the basal layer. Epithelization of the wound surface occurs from the marginal sections of the glands of the basal layer, as well as from the unrejected deep sections of the functional layer.
The fallopian tubes
The functional state of the fallopian tubes varies depending on the phase of the menstrual cycle. Thus, in the luteal phase of the cycle, the ciliated apparatus of the ciliated epithelium is activated, the height of its cells increases, over the apical part of which secretions accumulate. The tone of the muscular layer of the tubes also changes: by the time of ovulation, a decrease and intensification of their contractions are recorded, which have both a pendulum and rotational-translational character.
It is noteworthy that muscle activity is unequal in different parts of the organ: peristaltic waves are more characteristic of the distal parts. Activation of the ciliated apparatus of the ciliated epithelium, lability of the muscle tone of the fallopian tubes in the luteal phase, asynchronism and diversity of contractile activity in different parts of the organ are collectively determined to ensure optimal conditions transport of gametes.
In addition, in different phases The nature of microcirculation of the fallopian tubes changes during the menstrual cycle. During the period of ovulation, the veins that encircle the infundibulum in a ring and penetrate deep into its fimbriae become filled with blood, as a result of which the tone of the fimbriae increases and the infundibulum, approaching the ovary, covers it, which, in parallel with other mechanisms, ensures the entry of the ovulated egg into the tube. When the stagnation of blood in the annular veins of the funnel stops, the latter moves away from the surface of the ovary.
Vagina
During the menstrual cycle, the structure of the vaginal epithelium undergoes changes corresponding to the proliferative and regressive phases.
Proliferative phase corresponds to the follicular stage of the ovaries and is characterized by proliferation, enlargement and differentiation of epithelial cells. During the period corresponding to the early follicular phase, epithelial growth occurs mainly due to the cells of the basal layer; by the middle of the phase, the content of intermediate cells increases. In the preovulatory period, when the vaginal epithelium reaches its maximum thickness - 150-300 microns - activation of the cells of the surface layer is observed: the cells increase in size, their nucleus decreases, and becomes pyknotic. During this period, the glycogen content in the cells of the basal and, especially, intermediate layers increases. Only single cells are rejected.
The regressive phase corresponds to the luteal stage. In this phase, the growth of the epithelium stops, its thickness decreases, and some cells undergo reverse development. The phase ends with the desquamation of cells in large and compact groups.
Selected lectures on obstetrics and gynecology
Ed. A.N. Strizhakova, A.I. Davydova, L.D. Belotserkovtseva
In the body of a sexually mature, non-pregnant woman, regularly repeating complex changes occur that prepare the body for pregnancy. These biologically important rhythmically repeating changes are called the menstrual cycle.
The length of the menstrual cycle varies. For most women, the cycle lasts 28-30 days, sometimes it is shortened to 21 days, and occasionally there are women who have a 35-day cycle. It must be remembered that menstruation does not mean the beginning, but the end of physiological processes; menstruation indicates the attenuation of processes that prepare the body for pregnancy, the death of an unfertilized egg. At the same time, menstrual bleeding is the most striking, noticeable manifestation of cyclic processes, so it is practically convenient to begin calculating the cycle from the first day of the last menstruation.
Rhythmically repeating changes during the menstrual cycle occur throughout the body. Many women experience irritability, fatigue and drowsiness before menstruation, followed by a feeling of vigor and energy after menstruation. Before menstruation, an increase in tendon reflexes, sweating, a slight increase in heart rate, an increase in blood pressure, and an increase in body temperature by several tenths of a degree are also observed. During menstruation, the pulse slows down somewhat, blood pressure and temperature drop slightly. After menstruation, all these phenomena disappear. Noticeable cyclic changes occur in the mammary glands. In the premenstrual period, there is a slight increase in their volume, tension, and sometimes sensitivity. After menstruation, these phenomena disappear. During a normal menstrual cycle, changes in the nervous system occur within the limits of physiological fluctuations and do not reduce women’s ability to work.
Reaction of the menstrual cycle. In the regulation of the menstrual cycle, five links can be distinguished: cerebral cortex, hypothalamus, pituitary gland, ovaries, uterus. The cerebral cortex sends nerve impulses to the hypothalamus. The hypothalamus produces neurohormones that were called releasing factors or liberins. They in turn have an effect on the pituitary gland. The pituitary gland has two lobes: anterior and posterior. The posterior lobe accumulates the hormones oxytocin and vasopressin, which are synthesized in the hypothalamus. A number of hormones are produced in the anterior lobe of the pituitary gland, including hormones that activate the activity of the ovaries. Hormones of the anterior pituitary gland that stimulate the functions of the ovary are called gonadotropins (gonadotropins).
The pituitary gland produces three hormones that act on the ovary: 1) follicle-stimulating hormone (FSH); it stimulates the growth and maturation of follicles in the ovary, as well as the formation of follicular (estrogenic) hormone;
2) luteinizing hormone (LH), which causes the development of the corpus luteum and the formation of the hormone progesterone in it;
3) lactogenic (luteotropic) hormone - prolactin, promotes the production of progesterone in combination with LH.
In addition to FSH, LTG, LH gonadotropins, TSH is produced in the anterior lobe of the pituitary gland, which stimulates the work thyroid gland; HGH is a growth hormone; if it is deficient, dwarfism develops; if too much, gigantism develops; ACTH stimulates the adrenal glands.
There are two types of secretion of gonadotropic hormones: tonic (constant release at a low level) and cyclic (increased during certain phases of the menstrual cycle). An increase in FSH secretion is observed at the beginning of the cycle and especially in the middle of the cycle, around the time of ovulation. An increase in LH secretion is observed immediately before ovulation and during the development of the corpus luteum.
Ovarian cycle . Gonadotropic hormones are perceived by receptors (protein nature) of the ovary. Under their influence, rhythmically repeating changes occur in the ovary, which go through three phases:
a) follicle development - follicular phase, under the influence of FSH of the pituitary gland, from the 1st to the 14th – 15th day of the menstrual cycle with a 28-day menstrual cycle;
b) rupture of a mature follicle - ovulation phase, under the influence of FSH and LH of the pituitary gland on the 14th – 15th day of the menstrual cycle; During the ovulation phase, a mature egg is released from a ruptured follicle.
c) development of the corpus luteum - luteal phase, under the influence of LTG and LH of the pituitary gland from the 15th to 28th day of the menstrual cycle;
In the ovary in the follicular phase Estrogenic hormones are produced, they contain several fractions: estradiol, estrone, estriol. Estradiol is the most active; it mainly affects the changes inherent in the menstrual cycle.
During the luteal phase(development of the corpus luteum), in place of the ruptured follicle, a new, very important endocrine gland is formed - the corpus luteum (corpus luteum), which produces the hormone progesterone. The process of progressive development of the corpus luteum occurs during a 28-day cycle over 14 days and occupies the second half of the cycle - from ovulation to the next menstruation. If pregnancy does not occur, then from the 28th day of the cycle the reverse development of the corpus luteum begins. In this case, the death of luteal cells, emptying of blood vessels and proliferation of connective tissue occur. As a result, in place of the corpus luteum, a scar is formed - a white body, which subsequently also disappears. The corpus luteum is formed with each menstrual cycle; if pregnancy does not occur, it is called the corpus luteum of menstruation.
Uterine cycle. Under the influence of ovarian hormones formed in the follicle and corpus luteum, cyclic changes in the tone, excitability and blood supply of the uterus occur. However, the most significant cyclic changes are observed in the functional layer of the endometrium. The uterine cycle, like the ovarian cycle, lasts 28 days (less often 21 or 30-35 days). It distinguishes the following phases: a) desquamation;
b) regeneration; c) proliferation; d) secretion.
Desquamation phase manifested by menstrual bleeding, usually lasting 3-7 days; This is actually menstruation. The functional layer of the mucous membrane disintegrates, is rejected and is released out along with the contents of the uterine glands and blood from the opened vessels. The phase of endometrial desquamation coincides with the beginning of the death of the corpus luteum in the ovary.
Regeneration phase(restoration) of the mucous membrane begins during the period of desquamation and ends by the 5th - 7th day from the beginning of menstruation. Restoration of the functional layer of the mucous membrane occurs due to the proliferation of the epithelium of the remnants of the glands located in the basal layer and the proliferation of other elements of this layer (stroma, vessels, nerves).
Proliferation phase endometrium coincides with the maturation of the follicle in the ovary and continues until the 14th day of the cycle (with a 21-day cycle until the 10-11th day). Under the influence of estrogen (follicular) hormone proliferation (growth) of the stroma and growth of the glands of the endometrial mucosa occur. The glands stretch out in length, then twist like a corkscrew, but do not contain a secretion. The vascular network grows, the number of spiral arteries increases. The mucous membrane of the uterus thickens 4-5 times during this period.
Secretion phase coincides with the development and flowering of the corpus luteum in the ovary and lasts from the 14-15th day to the 28th, i.e. until the end of the cycle.
Under the influence of progesterone Important qualitative transformations occur in the uterine mucosa. The glands begin to produce secretions, their cavity expands. Glycoproteins, glycogen, phosphorus, calcium, trace elements and other substances are deposited in the mucous membrane. As a result these changes conditions favorable for the development of the embryo are created in the mucous membrane. If pregnancy does not occur, the corpus luteum dies, the functional layer of the endometrium, which has reached the secretion phase, is rejected, and menstruation occurs.
These cyclic changes are repeated at regular intervals during a woman's puberty. The cessation of cyclic processes occurs in connection with physiological processes such as pregnancy and breastfeeding. Disorders of menstrual cycles are also observed with pathological conditions(serious illnesses, mental effects, malnutrition, etc.).
LECTURE: SEX HORMONES OF WOMEN AND MEN, THEIR BIOLOGICAL ROLE.
Sex hormones are produced in the ovaries - estrogens, androgens, produced by the cells of the inner lining of the follicle, progesterone-yellow body. Estrogens are distinguished between more active ones (estradiol and estrone, or folliculin) and less active ones (estriol). In terms of their chemical structure, estrogens are close to the hormones of the corpus luteum, adrenal cortex and male sex hormones. All of them are based on a steroid ring and differ only in the structure of the side chains.
ESTROGEN HORMONES.
Estrogens are classified as steroid hormones. The ovaries produce 17 mg of estrogen-estradiol per day. Largest quantity it is secreted in the middle of the menstrual cycle (on the eve of ovulation), the least - at the beginning and at the end. Before menstruation, the amount of estrogen in the blood decreases sharply.
In total, the ovaries produce about 10 mg of estrogen during the cycle.
The effect of estrogen on a woman’s body:
- During puberty, estrogen hormones cause the growth and development of the uterus, vagina, external genitalia, as well as the appearance of secondary sexual characteristics.
- During puberty, estrogenic hormones cause regeneration and proliferation of cells in the uterine mucosa.
3. Estrogens increase the tone of the muscles of the uterus, increase its excitability and sensitivity to substances that contract the uterus.
4. During pregnancy, estrogen hormones ensure the growth of the uterus and the restructuring of its neuromuscular system.
5. Estrogens cause onset labor activity.
6. Estrogens promote the development and function of the mammary glands.
Starting from the 13-14th week of pregnancy, the placenta takes over the estrogenic function. With insufficient production of estrogen, primary weakness of labor is observed, which negatively affects the condition of the mother and especially the intrauterine fetus, as well as the newborn. They affect the level and metabolism of calcium in the uterus, as well as water metabolism, which is expressed by cyclic fluctuations in a woman’s weight associated with changes in water content in the body during the menstrual cycle. With the introduction of small and medium doses of estrogens, the body's resistance to infections increases.
Currently, the industry produces the following estrogen drugs: estradiol propionate, estradiol benzoate, estrone (folliculin), estriol (sinestrol), diethylstilbestrol, diethylstilbestrol propionate, dienestrol acetate, dimestrol, acrofollin, hogival, ethinylestradiol, microfollin, etc.
Substances that can neutralize and block the specific effects of estrogen drugs are called antiestrogens. These include androgens and gestagens.
Physiology of the menstrual cycle - section Sociology, Fundamentals of sexology and sexopathology The beginning of the Menstrual Cycle is usually considered the Day of the Appearance of Menstrual Flow...
The beginning of the menstrual cycle is usually considered the day the menstrual flow appears (day 1 of the cycle), and the end is the day preceding the start of the next menstruation. Cycle length varies from 21 to 40 days and averages 28 days (Vollman, 1977). Only a few women have such a regular cycle that they are able to accurately predict the day their period will begin.
The menstrual cycle is divided into three phases, which we describe in relation to the "average" 28-day cycle.
1. The first of these is called the follicular phase. In the ovary, follicles begin to mature - oval-shaped vesicles formed by epithelial cells and containing a young egg. At the beginning of this phase, the levels of estrogen and progesterone in the blood are quite low, and the endometrium is detached in the uterus, so that the bleeding surface is exposed. Exfoliated endometrial tissue together with blood forms menstrual flow, lasting 3-6 days.
In the middle of the follicular phase (approximately between the 7th and 10th days of the cycle), the secretion of estrogen by the ovaries increases and, under the combined influence of these hormones, the developing follicle begins to prepare for ovulation.
2. Ovulation phase - release of an egg from the ovary - as a rule, in most cases it occurs on the 14th day (with a 28-day cycle). However, we know of examples of 28-day cycles in which ovulation occurred on a variety of days from the 9th to the 19th, as well as cases where it did not occur at all. The ovulation phase is the shortest phase of the menstrual cycle.
3. The third phase of the menstrual cycle, called luteal, occurs immediately after ovulation and continues until the beginning next cycle. Its name comes from the Latin name for the corpus luteum (corpus luteum), a cell mass that forms in the ovary at the site of rupture of the follicle after ovulation. The corpus luteum secretes large quantities progesterone and estrogen, these changes prepare the uterus to receive a fertilized egg.
If fertilization of the egg does not occur, the corpus luteum degenerates 10-12 days after ovulation, hormone secretion drops sharply and the next menstruation occurs. Thus, menstruation occurs as a result of a sudden cessation of hormonal stimulation of processes in the endometrium.
End of work -
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St. Petersburg, 2012
As a result of studying the discipline, the student must: Know: · the history of the development of human sexual relations and the development of the science of sexology, · psychophysiological aspects of sexuality
Scope of discipline and types of academic work
Type of academic work Total hours Semesters Auditor
Questions for self-testing knowledge
Topic 1. Introduction. The concept of sexology as a science. Development of scientific sexology. 1. Why does a psychologist need to study and know sexology? 2. sec value
Topic 1.
Introduction. The concept of sexology as a science. Development of scientific sexology. There are many different reasons that I do
Sexuality is experienced and expressed
· in thoughts, · fantasies, · desires, · beliefs, · attitudes, · values, · actions, · roles and relationships.
In behavior, constructive sexuality is manifested by the ability
· enjoy the variety and richness of experiences that arise in a situation of sexual interaction while simultaneously delivering pleasure to the partner, · freedom from sexual predicaments
Destructive sexuality manifests itself in behavior
· inability to establish deep, intimate relationships, · avoidance of emotional intimacy as a burdensome duty or threat of loss of one’s own freedom, trust
A personality with pronounced destructive sexuality is characterized by
Ø inability for spiritually and emotionally fulfilling sexual partner interaction, for sexual “game”, Ø perceiving the partner only as an object (tool) d
Deficient sexuality is manifested in behavior
· low sexual activity or its absence; · avoidance of real sexual contacts, up to complete abandonment of them, · a tendency to replace real sexual relationships
A person with pronounced deficient sexuality is characterized by
Ø lack of sexual desires, Ø poverty of erotic fantasy, Ø weak emotionality even in personally significant relationships, Ø
Imelinsky K. (Sexopathology and sexology. M. 1986.)
In the development of sexology, 4 periods can be distinguished: the prehistoric period, characterized by limited information about the sexual life of prehistoric people;
Prehistoric period
Primitive man was not indifferent to the sexual sphere. Rock paintings of the Early Paleolithic (1 million - 100,000 years BC), which includes the first stage of the development of human culture, testify
Period of observations and pre-scientific research
In ancient times - in Western, Chinese, Indian and Arab cultures, they wondered about the value of sexuality, tried to classify various sexual behaviors with philosophical
The period of sexological knowledge covers the 19th century, in which sexology originated, but had not yet emerged as an independent discipline.
... In the 20th century, various branches of science began to study manifestations of sexuality within their competence. And although the methodology of these studies was still meager, many facts emerged that
Ancient times
Although we have written historical records dating back almost 5,000 years, information about sexual behavior and attitudes toward sex in different societies predates the first millennium.
The Ancient East
In other parts of the world, ideas about sex were very different from those just described. Followers of Islam, Hinduism and the Ancient East had a much more positive attitude towards sex.
Middle Ages and Renaissance
Throughout the 12th and 13th centuries, as the church gained increasing influence, early Christian attitudes toward sexuality became stronger in Europe. Theology is often
Eighteenth and nineteenth centuries
When we discuss the customs that existed in a particular historical era, we must remember that they differed in different countries, in different sectors of society or religious groups.
Multidimensionality of gender determination. Sexual dimorphism, Sexual differentiation
1. Determination of sex. In accordance with the modern multi-level model of sex determination (G.S. Vasilchenko et al., 1977), the following are distinguished:
Genetic disorders
A true hermaphrodite is a person who has both testicular and ovarian tissue at birth. Some hermaphrodites have fully formed testicles and ovaries, sexes
The effect of drugs on the developing fetus
Hormones prescribed to pregnant women for medical reasons cross the placenta into the bloodstream of the developing fetus. Degree of influence hormonal drugs on anatomical parameter
After the birth of a child, biological factors of sexual differentiation are supplemented by social ones.
Based on the genital appearance of a newborn, his civil gender is determined (otherwise it is called passport, obstetric or ascriptive, i.e. assigned gender), in
Interaction of biological and social factors
Many researchers believe that a child's gender identity is the result of the interaction of biological and psychosocial factors. In other words, n
Sexual dimorphism, Sexual differentiation
Problem psychological differences between men and women for a long time was surrounded by all sorts of myths. The first researchers of this problem, who set themselves the task of determining which of
Masculinity and femininity
Most people not only believe in the reality of differences between men and women, but also have approximately the same perceptions of these differences (Broverman et al., 1972). This kind of conviction
Androgyny
As you read this chapter, you may have noticed that you have both masculine and feminine traits in your personality. If this is true, then you are like most people. Only very few are inherent in
Birth and infancy
The exclamation that announces the gender of the child at the moment of his birth (“It’s a boy!” or “Girl!”) begins a whole chain of events: the choice of a pink or blue bracelet,
Masculinity
In the field of modern social sciences, there are different concepts of masculinity, which range from essentialist to social constructivist. Ø
Male reproductive system
It is much easier for a man to see and feel his genitals than for a woman to see hers. It is unlikely that a boy can remain ignorant of the sexual aspects of this organ. He finds out about them, touch
A mature human sperm is much smaller than an egg; its length reaches 0.06 mm, and its volume is thousands of times smaller than an egg
The sperm can only be seen under a microscope; it consists of three parts: head, body and tail. The head of the sperm contains genetic material, i.e. chromosomes, and
Female reproductive system
Vulva. The female external genitalia, forming the vulva, consists of the labia majora and minora, the clitoris and the perineum. Although the vagina has an external opening (entrance to the vaginal
Menstruation
Menstruation is called bloody issues, observed approximately once a month in most women aged 12 to 48 years. Although menstruation is part of the reproductive cycle
Conception process
Pregnancy occurs as a result of the meeting of a sperm and an egg. For this to happen, the sperm must enter the vagina shortly before ovulation. In this case, the sperm with
Fusion of sperm and egg
After ovulation, the egg is gently released from the surface of the ovary and passes into fallopian tube, along which, driven by cilia (small hair-like outgrowths), it
Fertilization
Sperm remain in the woman’s genitals for several hours. During this time, a little-studied process of capacitation occurs with them, as a result of which they become able to penetrate the egg
Pregnancy
Pregnancy lasts on average 266 days. To make it easier to describe the events occurring during this time, pregnancy is divided into three trimesters. The first trimester refers to the first three months after
Works by Master and Johnson on the physiology of sexuality
To obtain general idea about the nature of sexual reaction, Masters interviewed 18 female prostitutes and 27 male prostitutes. Then the laboratory installed instruments traditionally used
WITH scientific point From a perspective, sexual arousal can be defined as the activation of a complex system of reflexes that involves the genitals and the nervous system. Heads
Female orgasm
Until the middle of the 20th century. Many people (including doctors) believed that women were incapable of orgasm. This idea undoubtedly reflected the existing view of society on
Resolution phase
The sexual responses of men and women immediately after orgasm are very different. Women are physically capable of repeated orgasms within a short period of time
Three-phase model of the sexual response cycle
American sexologist Helen Singer Kaplan (H.S. Kaplan) proposed a three-phase model of the sexual cycle (1991-1995): Ø desire Ø desire
Widespread Myths About Sexual Responses
1. It is generally accepted that a man’s sexual abilities are more developed than a woman’s. In fact, everything is just the opposite. In terms of their physical capabilities, women have almost no
The concept of sexual constitution
In sexological practice, there is a need to correlate the intensity of the sexual life of an individual who seeks help, not only with his age, but also with objective parameters that determine
The scale of vector determination of the sexual constitution of women was proposed by I.L. Botneva
Genotype is the most stable part of the sexual constitution, independent of upbringing or partner; in women it is determined by the first 4 indicators,
achieving 50-100% orgasmicity
The calculation of the indices (Kg), (Ka) and the general index (K) is carried out similarly to the male version. Table 3.
Social aspects of sexuality and gender psychology
As noted by I.S. Kon, the sociocultural approach in sexology covers a wide range of studies, which are based on the following principles and theses:
Sex roles and sexual behavior
Traditional ideas about gender roles significantly influence sexual relationships between people and their sexual behavior. These stereotypes also affect the nature of behavior; men are trying
Double standard
The reflection of the unbalanced effect of prohibitions (“what and who is allowed and what and who is not allowed”) is illustrated by the current so-called double standard of sexual morality
Sex and gender equality
Most men and women eventually learn that the pleasure both partners desire cannot be achieved as long as sex remains something the man does for himself
Gender identity means that a person accepts their culture's definitions of masculinity and femininity
The concept of identity was first presented in detail by E. Erikson. From the point of view of E. Erikson, identity is based on awareness of temporal extension
The etiological factors and pathogenetic mechanisms of homosexuality are completely unknown
According to the neuroendocrine theory, homosexuality is determined by disturbances in the process of sexual differentiation of the brain in the prenatal period. Disorders of sexual differentiation of the brain
Isaev D.D. holds a slightly different opinion. In particular, he writes the following
“One of the most complex and poorly developed issues remains the question of the sexual (gender) identity of homosexuals... Attempts to implement a typology of homosexuality have been made more than once
An extensive scientific study allowed D. Isaev to identify groups of homosexually oriented men with different identities
1. “The substantive basis of the identity of homosexuals of the first group was the identification conflict between the self-perception of bodily femininity (more precisely, insufficient masculinity) and the desire
Ego-dystonia and ego-syntonia
The concepts of ego-syntonia and ego-dystonia are of particular interest for accompanying clients with problems of sexual orientation. Homosexuality is ego-syntonic when
Biopsychological drive/instinct theory
The original explanation of psychosexual development was based on the idea of an innate “sexual instinct.” People are born with certain sexual organs that
Psychodynamic theory
Psychodynamic theory, as its name suggests, considers primarily the dynamics of mental activity. Deepening the concept of instinct, Sigmund Freud put forward the end
Conditioning and social learning theory
At the initial stage of its development, psychology paid great attention to the study of the mechanisms by which animals adopt certain behavioral stereotypes.
Within the framework of this concept, special importance is not attached to such a factor as sexual desire
Researchers who adhere to this approach emphasize that the process of development of sexual behavior is influenced by many different factors.
Universal theoretical model of psychosexual development
Researcher John Bancroft (1990) proposed a universal theory of psychosexual development, which takes into account the various stages of physical and mental development
Stages of formation and development of libido
LIBIDO (lat. libido - attraction, desire, desire; synonym - sexual desire): the desire for sexual intimacy. Mature sexual desire is characterized by se
Childhood sexuality
Childhood is an unknown page in gender research, since reliable data regarding sexual behavior during this period are not available for objective reasons. Conclusions based
Sexuality in infancy
results ultrasound examination indicate that reflex erection in male fetuses occurs several months before birth, i.e. during intrauterine development
Sexuality at school age
Six- and seven-year-old children are usually already very aware of the main anatomical differences between people of different sexes and, as a rule, understand the inappropriateness of nudity in public. Undoubtedly
Puberty hormones and sexuality
The increasing production of hormones during puberty contributes to the awakening of sexual sensations, erotic thoughts and fantasies in both boys and girls. John Money as follows
The connection between sexual development and the idea of one’s own physical and spiritual appearance
Teenage children want to look attractive. This desire has a lot to do with how they perceive own body, what image of him they have for themselves
Knowing your own body, its sensual and sexual needs and reactions
Teenagers are concerned not only with their appearance, but also with exploring their own bodies. This is not as simple as it may seem, since adults do not always take the trouble to explain all aspects to them
Formation of gender self-identification
Renowned psychologist Erik Erikson (1968, 1985) believed that acquiring a sense of gender identity and overcoming the uncertainty that accompanies this process is central to sexual development.
Knowledge of sexual and love relationships between people
A child begins to explore sexual and love relationships between people in early adolescence, when boys and girls develop the necessary social communication skills in the process of growing up.
Formation of an individual system of sexual values
The formation of an individual system of sexual values occurs in parallel with the search for oneself and represents an important aspect of adolescent development. Answering the question: "What am I like?
Psychosocial characteristics of adolescence
1. Sexual fantasies Sexual fantasies and dreams in adolescents are more common and more pronounced than in younger children; they often accompany masturbation
Features of sexual behavior. Masturbation
Despite the widespread prevalence of this phenomenon, feelings of guilt and anxiety continue to torment teenagers who engage in masturbation. According to Sorenson (1973), such negative
Homosexual relationships
Kinsey's research has shown that many men engage in homosexual relationships at least once during adolescence. Among teenage girls, such relationships are much more common.
Consequences of sexual activity
Most authors who have studied the consequences of sexual activity in adolescents have focused on cases of unintended pregnancy. Social and psychological consequences of ra
Aspects of sexual identity in adolescence
For some young people, sexual identification is a major part of their overall identity; for others, it is a smaller part. Like many adults, most teenagers have both
“As much as we might wish otherwise, children are born sexually motivated, and parents constantly give them sex education lessons, consciously or unconsciously.
Principles of sex education
Ø The most important thing in sex education for children is the formation of a positive attitude towards lovers, towards intimate relationships and the birth of a child. Already at early preschool age, children begin to form
Conversations with children 3-5 years old
At this age, children acquire knowledge about their body and the basic facts of life, and they develop an awareness of belonging to a particular gender. They start asking where babies come from and...
Conversations with children 6-8 years old
Children of this age understand the more complex aspects of such phenomena as health, illness, death. They are interested in such things as birth, marriage, the role of the father in childbirth. All children show
Conversations with children 9-12 years old
In the body of children of this age, changes inherent in puberty. Teenagers are extremely interested in their own body and appearance, which should be considered the norm. For some
Key elements of compulsory sex education programs
It would be a mistake to prescribe any particular sex education program to a school, since planning the thematic content of the program and choosing the main approaches to presenting the material is
Absence of organic disorders, diseases interfering with sexual and reproductive functions
The ability to enjoy and control sexual behavior is formed gradually in the process of psychosexual development, therefore, before the onset of a certain maturity, from a formal point of view,
Identity and identification
The most important mechanism for the formation and maintenance of stability of self-awareness is identification. On the one hand, this concept means likening, identifying with someone or something, with
Gender identity
A particular aspect of self-awareness is gender identity. I.S. Kon (1988) defines gender identity as “the unity of behavior and self-awareness of an individual who considers himself
He considers the reason for this to be the repressive attitude of the environment towards the masculine behavior of boys given the masculine orientation of sexual culture in general.
In boys with feminine traits, the risk of psychological maladjustment increases with age; their systemic organization of character is represented by more conflicting and potentially pathogenic combinations.
Gender role, gender role identity
The gender role is understood as a model of behavior, a system of instructions that an individual must learn and conform to in order to be recognized as a man
Middle age crisis
In the context of their sexual lives, men seem to experience such a crisis especially often. There is an opinion that at forty men are past their peak." sexy shape"Having heard about this, many
Sexual burnout
Another significant feature of the midlife crisis that is usually forgotten is sexual burnout, a phenomenon that affects up to 20% of all individuals in a given age. age group(Kolodny, 1983
Other aspects
Most men “discover” their sexuality in that joyful time when they are not yet twenty years old. At the same time, a significant part of women (at least in the past
Menopause
With age, a woman loses her ability to bear children. The weakening of reproductive function begins after 30 years and is initially expressed in a decrease in the likelihood of conception and an increase in the number of spontaneous
Elderly age
In America, it is generally accepted that sex is an activity for young, healthy and attractive people. People who have just entered puberty tend to feel awkward about the idea of sex.
Biological aspects of aging
Aging in itself does not reduce a woman's sexual interests or her potential ability to respond to sexual stimuli, provided she is in normal general health
Psychosocial aspects
Society's negativity towards love and sex in old age is partly generated by a phenomenon called ageism - prejudice against people because they are old.
Pathological sexual deviations
A. Progressive forms (sexual perversions). B. Impulsive forms. Sexual disorders will be discussed in detail below in the relevant topics. I gave it here
Paraphilia
(from the Greek words “para” - near, near, and “philia” - attraction), that is, “wrong attraction”. Paraphilia does not necessarily violate social norms or represent
But if this same stimulus becomes an indispensable condition for sexual satisfaction, then this is already a deviation
A person’s awareness of his differences in behavior and feelings often leads to the emergence of an internal conflict, the strength of which depends on the attitude of society towards that or
Sadistic personality
For a sadist, sexual pleasure is possible only with complete dominance, unlimited dominance over a partner, mastering him and subjugating him to such an extent that he can even be hurt
Sexual crime, according to some modern data, is the result of the development of aggressive-sadistic tendencies of the individual
Ø In old works, it was argued that sexual offenses are a consequence of an irresistible desire to immediately satisfy one's sexual passion. Ø
There are simpler explanations
Ø the child experienced the first erotic sensations during a spanking, and in the future he associates sexuality with a spanking or a belt. This is one of the most dangerous and unpredictable
Types of sadomasochism
Name Description Dippoldism A type of flagellantism, which is associated with the teacher receiving sexual satisfaction from physical
Sexual deviations in relation to the object. Pedophilia; gerontophilia; bestiality; fetishism; transvestism
Pedophilia (from the Greek words "pedes" - child and "philia" - attraction) - sexual attraction to children - occurs among both heterosexual and
Ephebophilia (from the Greek word "ephebe" - teenager, youth) - sexual attraction to persons of adolescence and youth
Attraction to 14-16 year olds is not a psychiatric diagnosis, although in most countries, including Russia, sexual relations between adults and persons of this age are prohibited by law. IN
Gerontophilia - sexual attraction to elderly and senile people
The origins of gerontophilia lie in the child’s attitude towards an adult as an ideal, an idol, a role model. Lack of attention to oneself, disruption of communication with parents, lack of care with one hundred
Necrophilia is sexual attraction to corpses and performing sexual acts with them. Extremely rare
Orgasm in children of both sexes is often combined with an affect of fear and anxiety, which is why the primary neutral anxious state (for example, the upcoming Classwork) can cause orgasm. For sex
True transvestism is a perversion in which cross-dressing causes sexual pleasure
For transvestites, it is women's clothing that gives maximum sexual pleasure, but the rest of the time they dress and behave like other men. Changing clothes is often combined with looking at oneself
Transvestism can have different reasons and motives
Ø In one case, it is directly related to the circumstances that caused the first strong sexual arousal: the boy puts on his older sister’s underwear, the unusual situation causes him strong
Transsexualism. Gender identity disorders
Transsexualism is an emotional and mental characteristic of a person who denies his biological sex. IN last years The prevailing opinion among experts is that sexual
The phenomenon of transsexuality
In 1953, the world was shocked by the news that Christine Jorgensen, a former US Marine, had undergone sex reassignment surgery in Denmark from male to female. Since then transsexual
It is assumed that both biological and psychological factors are involved in the formation of the transsexual condition
In the most fully studied cases of transsexuality, subjects are characterized by a lifelong sense of inadequacy between what gender they perceive themselves to be and who they are.
Transsexualism
The desire to exist and be accepted as a person of the opposite sex, usually combined with feelings of inadequacy or discomfort with one's anatomical sex and a desire to obtain hormones
Double role transvestism
Wearing clothes appropriate opposite sex, as part of a lifestyle with the aim of obtaining pleasure from the temporary feeling of belonging to the opposite sex, but without the slightest desire
Gender identity disorder in children
Includes a range of disorders that first appear in childhood and always before the onset of puberty, which are characterized by constant expressed dissatisfaction with the sex of registration, which is accompanied by an onset
Features of sexual disorders (dysfunctions). “Norm” and sexual health
Sexual health. Defining the concept of human sexual health is quite difficult. It should include not only psychological, physiological and
Norm in sexology
First of all, it is necessary to remember that the concept of norm is ambiguous in clinical psychology. A meaningful definition of a clinical norm as a theoretical construct is a major methodological
B.S. Bratus (1988) developed the concept of “normal development”
The conditions and criteria for this development are: Ø treating another person as an intrinsic value, as a being who embodies the endless potential of the “human” species
Disorders associated with the phase of sexual attraction (desire)
Sexual desire, or libido, is the desire for sexual intercourse associated with erotic-sexual activity. Abnormal increase
Sexual anorexia
A complete loss of sexual desire (sexual anorexia) can be caused by psychogenic factors, but can equally become a biological manifestation of depression, alcoholism, intoxication
Sexual avoidance disorders and sexual phobias
The immediate manifestations of sexual avoidance disorders are the patient's irrational fear or complete aversion to sex. Patient's obsessive fear
Carrying out sexual intercourse. Sexual arousal phase
To have sexual intercourse, a man must have an appropriate erection, which appears involuntarily during sexual arousal. Insufficient erection or its absence, as well as its short duration
Orgasm phase
Achieving orgasm can be significantly easier or more difficult. A woman's rapid achievement of orgasm rarely becomes a matter of concern for her, since she can continue without any difficulty.
erectile disfunction
To have sexual intercourse, a man must have an appropriate erection, which appears involuntarily during sexual arousal. Insufficient erection or its absence, as well as its short duration
Psychogenic impotence
The leading pathogenetic link of psychogenic impotence is a decrease in the sensitivity of cavernous tissue to the effects of erectile neurotransmitters as a result of the direct inhibitory influence of the cortex
Diseases and other reasons
It is important to keep in mind that about 50% of extracorporeal dialysis patients suffer from erectile dysfunction. At the same time, after a successful kidney transplant, potency is restored in
Psychological factors
There is an opinion that about 50% of men experience some kind of difficulty with erection, and these difficulties arise on an organic basis in 15% of cases. Contributing
Then the organic cause of impotence is excluded, and you don’t have to spend money on unnecessary and expensive diagnostic tests
The signs that distinguish functional changes from organic ones are the following: Ø the occurrence of an erection during sleep, in connection with the phase of rapid eye movements, in advance
Individuals who have sexual experience, in the absence of any failures in their sexual life, develop disbelief in the success of the upcoming copulation
Against the backdrop of excessive concentration of attention on the sexual sphere and the functioning of the genital organs, attempts at constant self-control, fear of sexual life, coitus, and persons of contraband develops.
The condition of priapism requires medical intervention
Orgasm disorders (orgasmic dysfunction) It should be noted that normally orgasm in men is closely related to ejaculation, therefore in this disorder
Inability to control ejaculation sufficiently to ensure that both partners enjoy sexual intercourse
Premature ejaculation can be caused by psychogenic and organic factors (diseases of the male genital organs, organic brain lesions).
There are absolute and relative forms of premature ejaculation
ü In the first case, the duration of sexual intercourse is less than one minute (less than 20 frictions) against the background of regular sexual activity, ü in the second - the duration of sexual intercourse is
Psychotherapeutic treatment of psychogenically caused and combined sexual disorders in men should be based on the reasons that caused them
It is extremely important to determine: ü whether the disorders are individual, or ü partner. Shown personally oriented psychotherapy, possible
The nosological unit of sexual dysfunctions in women, adopted in 1999 by WHO, combines a wide range of sexual disorders in women: disturbances in the phase of desire, arousal, and achievement
Frigidity
Frigidity (sexual coldness) is a complete absence or decrease in a woman’s sexual desire, specific sexual sensations and orgasm. In some cases, frigidity may be accompanied by cravings
However, disturbances of the orgasm phase are possible in the absence of disorders of the first two phases
Occasionally, women with low sex drive may experience arousal and orgasm due to effective sexual stimulation, although this is very rare. From Russian
Mental and physical fatigue are the most common causes of temporary weakening of a woman’s libido
When called gynecological diseases symptomatic libido frigidity, erotic dreams, extracoital orgasm and sensitivity erogenous zones may remain intact.
Anorgasmia
Anorgasmia means the absence of a sensual “peak” (orgasm) during sexual stimulation. As an independent sexual disorder
There are 3 degrees of severity of vaginismus
Ø In the extreme form, the entrance to the vagina is compressed so much that it is impossible to insert not only the penis, but even a finger into it. Ø For more soft form vaginismus any attempts
Sexual disharmony can manifest itself in different ways
In one case, there is an unequal level of sexual desire: he wants to have intercourse more often than she, or vice versa. This is the most common partner dysfunction; according to subs
Unconscious causes of sexual disharmony
S. A. Chernysheva (Moscow)] Materials of the scientific-practical conference "Sexual culture and sexual health of the nation." May 12, 2002, P
Multidimensionality of gender determination. Sexual dimorphism. Sexual differentiation
Issues for discussion: 1. Determination of gender. The sequence of sex formation in humans: chromosomal (genetic) sex, gonadal, hormonal sex. 2. Formation
Social aspects of sexuality and gender psychology. Homosexual personality orientation
Issues for discussion: Sociocultural approach to sexology. Psychosexual culture, its possibilities, forms of transmission. Permission (permissive) and p
Sex education and enlightenment. Gender identity. Sexual health
Issues for discussion: Repressive, avoidant, intrusive and expressive types of parental attitudes towards gender issues. Sex education as a process of gender
Psychosexual identification and gender role identity
Issues for discussion: 1. Concepts of identity and identification. 2. E. Erikson's theory of identity. 3. Gender identity as a unity of behavior and self-awareness
Sexual deviations “according to the method of implementation.” Sadism, masochism, sadomasochism. Exhibitionism, voyeurism
Questions for discussion: Sadism – definition, origin of the term. Sadistic inclinations - realization in action and fantasy. Combination with other deviations.
Sexual deviations in relation to the object. Pedophilia, gerontophilia, bestiality, fetishism, transvestism
Issues for discussion: Pedophilia, definition of the concept, reasons. Negative consequences for pedophilic objects. Attraction to 14-16 year olds is ephebophilia.
Sexual disorders in men
Issues for discussion: Erectile dysfunction. Primary, secondary erectile dysfunction, (selective) erectile dysfunction. Classification of erectile dysfunction
Sexual disorders in women
Issues for discussion: Decreased sexual desire. Frigidity Classifications of frigidity. Anorgasmia. Prevalence. Primary and secondary
Family and sexual disharmony (dysgamy)
Issues for discussion: 1. Diagnosis of family and sexual disharmony. 2. Most characteristic features dysgamy. 3. The variety of causes of partner dysfunctions
Transsexualism
conviction of the “wrongness” of one’s biological sex, desire to belong to the opposite sex. Accompanied by a desire to change sex (surgically) and imitation of behavior
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. Reproductive period characterized by the ability of a woman’s body to reproduce offspring; The duration of this period is from 17-18 to 45-50 years. The reproductive, or 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 transitions into menopause, in which premenopause, menopause 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.
Menstruation is bloody discharge from a woman’s genital tract that periodically occurs as a result of the rejection of the functional layer of the endometrium at the end of a two-phase menstrual cycle. 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, and then a regular menstrual cycle is established.
The first day of menstruation is conventionally taken as the first day of the menstrual cycle. Therefore, the length of the cycle is the time between the first days of the next two menstruation periods. For 60% of women, the average length of the menstrual cycle is 28 days, ranging from 21 to 35 days. The amount of blood loss on menstrual days is 40-60 ml, on average 50 ml. The duration of normal menstruation is from 2 to 7 days.
Ovaries. During the menstrual cycle, follicles grow in the ovaries and the egg matures, which eventually becomes ready for fertilization. At the same time, sex hormones are produced in the ovaries, which ensure changes in the mucous membrane of the uterus, capable of receiving a fertilized egg.
Sex hormones (estrogens, progesterone, androgens) are steroids; granulosa cells of the follicle, cells of the inner and outer layers, take part in their formation. Sex hormones synthesized by the ovaries affect target tissues and organs. These include the genital organs, primarily the uterus, mammary glands, spongy bones, brain, endothelium and smooth tissues. muscle cells blood vessels, myocardium, skin and its appendages (hair follicles and sebaceous glands) etc. Direct contact and specific binding of hormones on the target cell is the result of its interaction with the corresponding receptors.
The biological effect is provided by free (unbound) fractions of estradiol and testosterone (1%). The bulk of ovarian hormones (99%) are in a bound state. Transport is carried out by special proteins - steroid-binding globulins and nonspecific transport systems- albumin and erythrocytes.
A - primordial follicle; b - preantral follicle; c - antral follicle; d - preovulatory follicle: 1 - oocyte, 2 - granulosa cells (granular zone), 3 - theca cells, 4 - basement membrane.
Estrogenic hormones contribute to the formation of genital organs and the development of secondary sexual characteristics during puberty. Androgens influence the appearance of pubic hair and armpits. 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.
2. Ovulation.
3. Education, development and regression of the corpus luteum.
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 300-400 mature to the ovulation stage.
It is customary to distinguish the following main stages of follicle development (Fig. 2.12): primordial follicle, preantral follicle, antral follicle, preovulatory follicle.
The primordial follicle consists of an immature egg, which is located in the follicular and granulosa (granular) epithelium. The outside of the follicle is surrounded by a connective membrane (theca cells). During each menstrual cycle, 3 to 30 primordial follicles begin to grow and form preantral, or primary, follicles.
Preantral follicle. As growth begins, the primordial follicle progresses to the preantral stage, and the oocyte enlarges and is surrounded by a membrane called the zona pellucida. Granulosa epithelial cells undergo proliferation, and the theca layer is formed from the surrounding stroma. This growth is characterized by an increase in estrogen production. Cells of the granulosa layer of the preantral follicle are capable of synthesizing three classes of steroids, while much more estrogens are synthesized than androgens and progesterone.
Antral, or secondary, f o l l i k u l. It is characterized by further growth: the number of cells of the granulosa layer producing follicular fluid increases. Follicular fluid accumulates in the intercellular space of the granulosa layer and forms cavities. During this period of folliculogenesis (8-9 days of the menstrual cycle), the synthesis of sex steroid hormones, estrogens and androgens is noted.
According to modern theory synthesis of sex hormones, androgens are synthesized in the theca cells - androstenedione and testosterone. Androgens then enter the granulosa layer cells and are aromatized into estrogens.
Dominant follicle. As a rule, one such follicle is formed from many antral follicles (by the 8th day of the cycle). It is the largest and contains the largest number of granulosa layer cells and receptors for FSH and LH. The dominant follicle has a richly vascularized theca layer. Along with the growth and development of the dominant preovulatory follicle in the ovaries, the process of atresia of the remaining (90%) growing follicles occurs in parallel.
The dominant follicle in the first days of the menstrual cycle has a diameter of 2 mm, which within 14 days at the time of ovulation increases to an average of 21 mm. During this time, there is a 100-fold increase in the volume of follicular fluid. The content of estradiol and FSH sharply increases in it, and growth factors are also determined.
Ovulation is the rupture of the preovular dominant (tertiary) follicle and the release of the egg. By the time of ovulation, the process of meiosis occurs in the oocyte. Ovulation is accompanied by bleeding from the destroyed capillaries surrounding the theca cells. It is believed that ovulation occurs 24-36 hours after the formation of the preovulatory estradiol peak. Thinning and rupture of the wall of the preovulatory follicle occurs under the influence of the enzyme collagenase. Prostaglandins F2a and E2 contained in follicular fluid also play a certain role; proteolytic enzymes produced in granulosa cells; oxytocin and relaxin.
After the release of the egg, the resulting capillaries quickly grow into the cavity of the follicle. Granulosa cells undergo luteinization: the volume of their cytoplasm increases and lipid inclusions form. LH, interacting with 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.
Thus, the main female reproductive organs are synthesized in the ovary steroid hormones- estradiol and progesterone, as well as androgens.
In phase I of the menstrual cycle, which lasts from the first day of menstruation until the moment of ovulation, the body is under the influence of estrogens, and in phase II (from ovulation to the beginning of menstruation), progesterone, secreted by the cells of the corpus luteum, joins estrogens. The first phase of the menstrual cycle is also called follicular, or follicular, the second phase of the cycle is luteal.
During the menstrual cycle in peripheral blood There are two peaks in estradiol content: the first, a pronounced preovulatory cycle, and the second, less pronounced, in the middle of the second phase of the menstrual cycle. After ovulation in the second phase of the cycle, progesterone is the main hormone, maximum amount which is synthesized on the 4-7th day after ovulation (Fig. 2.13).
The cyclic secretion of hormones in the ovary determines changes in the uterine mucosa.
Cyclic changes in the uterine mucosa (endometrium). The endometrium consists of the following layers.
1. The basal layer, which is not torn off during menstruation. During the menstrual cycle, its cells form the endometrial layer.
2. The superficial layer, consisting of compact epithelial cells that line the uterine cavity.
3. Intermediate, or spongy, layer.
The last two layers constitute the functional layer, which undergoes major cyclic changes during the menstrual cycle and is shed during menstruation.
In phase I of the menstrual cycle, the endometrium is a thin layer consisting of glands and stroma. The following main phases of changes in the endometrium during the cycle are distinguished:
1) proliferation phase;
2) secretion phase;
3) menstruation.
Proliferation phase. As the secretion of estradiol by growing ovarian follicles increases, the endometrium undergoes proliferative changes. There is an active proliferation of cells in the basal layer. A new superficial loose layer with elongated tubular glands is formed. This layer quickly thickens 4-5 times. Tubular glands, lined with columnar 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 stromal cells, increasing in volume, move closer to each other. The secretion of the glands increases. A copious amount of secretion is found in the lumen of the glands. Depending on the intensity of secretion, the glands either remain highly convoluted or take on a sawtooth shape. There is increased vascularization of the stroma. There are early, middle and late phase secretion.
Menstruation. This is the rejection of the functional layer of the endometrium. The subtle mechanisms underlying the occurrence and process of menstruation are unknown. It has been established that 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.
There are the following main local mechanisms involved in menstruation:
1) change in the tone of spiral arterioles;
2) changes in the mechanisms of hemostasis in the uterus;
3) changes in the lysosomal function of endometrial cells;
4) endometrial regeneration.
It has been established that the onset of menstruation is preceded by intense narrowing of the spiral arterioles, leading to ischemia and desquamation of the endometrium.
During the menstrual cycle, the content of lysosomes in endometrial cells changes. Lysosomes contain enzymes, some of which are involved in the synthesis of prostaglandins. In response to a decrease in progesterone levels, the release of these enzymes increases.
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 stromal cells, 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 the restoration of the integrity of ruptured arterioles, veins and capillaries.
Changes in the ovaries and uterus occur under the influence of the two-phase activity of the systems regulating menstrual function: the cerebral cortex, the hypothalamus, the pituitary gland. Thus, there are 5 main links in the female reproductive system: cerebral cortex, hypothalamus, pituitary gland, ovary, uterus (Fig. 2.14). The interconnection of all parts of the reproductive system is ensured by the presence in them of receptors for both sex and gonadotropic hormones.
The role of the central nervous system in regulating the function of the reproductive system has been known for a long time. This was evidenced by ovulation disorders in various acute and chronic stress, disruption of the menstrual cycle due to changes in climatic and geographical zones and work rhythm; The cessation of menstruation in wartime conditions is well known. In mentally unstable women who passionately desire to have a child, menstruation may also stop.
In the cerebral cortex and in extrahypothalamic cerebral structures (limbic system, hippocampus, amygdala, etc.), specific receptors for estrogens, progesterone and androgens have been identified. In these structures, the synthesis, release and metabolism of neuropeptides, neurotransmitters and their receptors occur, which in turn selectively influence the synthesis and release of hypothalamic releasing hormone.
The following neurotransmitters function in conjunction with sex steroids: norepinephrine, dopamine, gamma-aminobutyric acid, acetylcholine, serotonin and melatonin. Norepinephrine stimulates the release of gonadotropin-releasing hormone (GTRH) from neurons in the anterior hypothalamus. Dopamine and serotonin reduce the frequency and amplitude of GTRH production during various phases of the menstrual cycle.
Neuropeptides (endogenous opioid peptides, neuropeptide Y, corticotropin-releasing factor and galanin) also influence the function of the reproductive system, and therefore the function of the hypothalamus. Endogenous opioid peptides of three types (endorphins, enkephalins and dynorphins) are able to bind to opiate receptors in the brain. Endogenous opioid peptides (EOPs) modulate the effect of sex hormones on the content of GTRH through a feedback mechanism, block the pituitary gland's secretion of gonadotropic hormones, especially LH, by blocking the secretion of GTRH in the hypothalamus.
The interaction of neurotransmitters and neuropeptides ensures regular ovulatory cycles, influencing the synthesis and release of GTRH by the hypothalamus.
The hypothalamus contains peptidergic neuron cells that secrete stimulating (liberins) and blocking (statins) neurohormones - neurosecretion. These cells have the properties of both neurons and endocrine cells, and respond to both signals (hormones) coming from the bloodstream and neurotransmitters and neuropeptides from the brain. Neurohormones are synthesized in the ribosomes of the neuron cytoplasm and then transported along the axons to the terminals.
Gonadotropin-releasing hormone (liberin) is a neurohormone that regulates the gonadotropic function of the pituitary gland, where FSH and LH are synthesized. LH releasing hormone (Luliberin) has been isolated, synthesized and described in detail. To date, it has not been possible to isolate and synthesize follicle-stimulating hormone, or folliberin.
GnRH secretion has a pulsating nature: peaks of enhanced hormone secretion lasting several minutes are replaced by 1-3 hour intervals of relatively low secretory activity. The frequency and amplitude of GnRH secretion is regulated by estrogen levels.
The neurohormone that controls the secretion of prolactin by the adenohypophysis is called prolactin-inhibiting hormone (factor), or dopamine.
An important link in the reproductive system is the anterior lobe of the pituitary gland - the adenohypophysis, which secretes gonadotropic hormones, follicle-stimulating hormone (FSH, follitropin), luteinizing hormone (LH, lutropin) and prolactin (Prl), which regulate the function of the ovaries and mammary glands. All three hormones are protein substances (polypeptides). The target gland of gonadotropic hormones is the ovary.
The anterior lobe of the pituitary gland also synthesizes thyroid-stimulating (TSH) and adrenocorticotropic (ACTH) hormones, as well as growth hormone.
FSH stimulates the growth and maturation of ovarian follicles, promotes the formation of FSH and LH receptors on the surface of ovarian granulosa cells, increases the content of aromatase in the ripening follicle and, stimulating aromatization processes, promotes the conversion of androgens into estrogens, stimulates the production of inhibin, activin and insulin-like growth factor-1, which play an inhibitory and stimulating role in follicle growth.
LG stimulates:
Formation of androgens in theca cells;
Ovulation together with FSH;
Remodeling of granulosa cells during luteinization;
Synthesis of progesterone in the corpus luteum.
Prolactin stimulates mammary gland growth and lactation, controls the secretion of progesterone by the corpus luteum by activating the formation of LH receptors in them.
Rice. 2.14.
RHLH - releasing hormones; OK - oxytocin; Prl - prolactin; FSH - follicle-stimulating hormone; P - progesterone; E - estrogens; A - androgens; R - relaxin; I - inhibin; LH - luteinizing hormone.
Rice. 2.15.
I - gonadotropic regulation of ovarian function: PDH - anterior lobe of the pituitary gland, other symbols are the same as in Fig. 2.14; II - content in the endometrium of receptors for estradiol - RE (1,2,3; solid line) and progesterone - RP (2,4,6; dotted line); III - cyclical changes in the endometrium; IV - cytology of the vaginal epithelium; V - basal temperature; VI - tension of cervical mucus.
The synthesis of prolactin by the adenohypophysis is under the tonic blocking control of dopamine, or prolactin-inhibiting factor. Inhibition of prolactin synthesis ceases during pregnancy and lactation. The main stimulator of prolactin synthesis is thyrotropin-releasing hormone, synthesized in the hypothalamus.
Cyclic changes in the hypothalamic-pituitary system and in the ovaries are interconnected and modeled as feedback.
The following types of feedback are distinguished:
1) a “long loop” of feedback - between ovarian hormones and the nuclei of the hypothalamus; between ovarian hormones and pituitary gland;
2) “short loop” - between the anterior lobe of the pituitary gland and the hypothalamus;
3) “ultra-short loop” - between the GTRG and the nerve cells of the hypothalamus.
The relationship of all these structures is determined by the presence of receptors for sex hormones in them.
A woman of reproductive age has both negative and positive feedback between the ovaries and the hypothalamic-pituitary system. An example of negative feedback is the increased release of LH by the anterior pituitary gland in response to low level estradiol in the early follicular phase of the cycle. An example of positive feedback is the release of LH in response to the ovulatory maximum of estradiol in the blood.
The state of the reproductive system can be judged by assessing functional diagnostic tests: basal temperature, pupil symptom and karyopyknotic index (Fig. 2.15).
Basal temperature is measured in the rectum in the morning, before getting out of bed. During the ovulatory menstrual cycle, the basal temperature rises in the luteal phase of the cycle by 0.4-0.6 °C and remains the same throughout the second phase (Fig. 2.16). On the day of menstruation or the day before it, the basal temperature decreases. During pregnancy, an increase in basal temperature is explained by excitation of the thermoregulatory center of the hypothalamus under the influence of progesterone.
The menstrual cycle is the period of time from the first day of one menstruation to the first day of the next menstruation.
From lat. menstruus (“lunar cycle”, monthly) - periodic changes in the body of a woman of reproductive age, aimed at the possibility of conception. The beginning of the menstrual cycle is conventionally considered the first day of menstruation.
Duration of the menstrual cycle
The duration of the menstrual cycle (on average) is 28±7 days.
The duration of the cycle is determined by the physiological processes in the woman’s body.
Terminology
Menarche - the first menstrual cycle - is the central event during sexual development, indicating the female body's ability to reproduce. In humans, the average age of menarche is considered to be 12-14 years, with the norm from 9 to 15 years (9 years - early menarche, the onset of menarche after 15 years - primary amenorrhea). The time of the first menstrual bleeding depends on factors such as heredity, nutrition, and general health.
The cessation of menstruation occurs at the age of 40-58 years (on average, at 47-50 years), during menopause, reproductive function declines. The time of onset of menopause (menopause is a period characterized by irregularity or complete cessation of menstruation) depends largely on heredity, however, some diseases and medical interventions can cause early attack menopause.
Phases
The processes occurring during the menstrual cycle can be described as phases corresponding to changes in the ovaries (follicular, ovulatory and luteal) and in the endometrium (menstrual, proliferative and secretory phases).
Follicular/menstrual phase
The beginning of the follicular phase of the ovary or the menstrual phase of the uterus is considered to be the first day of menstruation. The duration of the follicular phase, during which the final maturation of the dominant follicle occurs, is individual for each woman: from 7 to 22 days, on average 14 days.
Ovulatory
Around the seventh day of the cycle, a dominant follicle is determined, which continues to grow and secretes increasing amounts of estradiol, while the remaining follicles undergo reverse development. A follicle that has reached maturity and is capable of ovulation is called a Graafian vesicle. During ovulatory phase, which lasts about three days, there is a release of luteinizing hormone (LH). Within 36-48 hours, several waves of LH release occur, and its plasma concentration increases significantly. The release of LH completes the development of the follicle, stimulates the production of prostaglandins and proteolytic enzymes necessary for rupture of the follicle wall and release of a mature egg (ovulation itself). At the same time, the level of estradiol decreases, which is sometimes accompanied by ovulatory syndrome. Ovulation usually occurs within 24 hours after the largest LH surge (16 to 48 hours). During ovulation, 5-10 ml of follicular fluid is released, which contains the egg.
Luteal/secretory phase
The period of time between ovulation and the onset of menstrual bleeding is called the luteal phase of the cycle (also known as the corpus luteum phase). Unlike the follicular phase, the duration of the luteal phase is more constant - 13-14 days (± 2 days). After the Graafian vesicle ruptures, its walls collapse, its cells accumulate lipids and luteal pigment, this gives it yellow. The transformed Graafian follicle is now called the corpus luteum. The duration of the luteal phase depends on the period of functioning (10-12 days) of the corpus luteum, during which time the corpus luteum secretes progesterone, estradiol and androgens. Elevated levels of estrogen and progesterone change the characteristics of the two outer layers of the endometrium. The endometrial glands mature, proliferate and begin to secrete (secretory phase), the uterus prepares for implantation of a fertilized egg. Progesterone and estrogen levels peak in the mid-luteal phase, and LH and FSH levels decrease in response.
When pregnancy occurs, the corpus luteum begins to produce progesterone until the placenta develops and secretes estrogen and progesterone.
If pregnancy does not occur, the corpus luteum stops functioning, the level of estrogen and progesterone decreases, which leads to swelling and necrotic changes in the endometrium. A decrease in progesterone levels also increases the synthesis of prostaglandins. Prostaglandins (PGs) cause vasospasm and contraction of the uterus, and the two outer layers of the endometrium are rejected. A decrease in the level of estrogen and progesterone also contributes to a decrease in GRF and the resumption of the synthesis of LH and FSH, and a new menstrual cycle begins.
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