Are you here: Questions

Hermaphroditism (named after the Greek god Hermaphrodite (Greek Ερμαφρόδιτος)) is the simultaneous or sequential presence of male and female sexual characteristics and reproductive organs in an organism.

There are natural hermaphroditism inherent in various species of animals and plants (monoecy) and abnormal (pathological) hermaphroditism of normally dioecious animals (see Gynandromorphism, Intersexuality).

Hermaphroditism is quite widespread in nature - both in the plant world (in this case the terms monoecy or polyecy are usually used) and among animals. Most higher plants are hermaphrodites; in animals, hermaphroditism is widespread primarily among invertebrates - a number of coelenterates, the vast majority of flatworms, some annelids and roundworms, mollusks, crustaceans (in particular, most species of barnacles) and insects (coccids).

Among vertebrates, many species of fish are hermaphrodites, and hermaphroditism is most common in fish inhabiting coral reefs.

With natural hermaphroditism, an individual is capable of producing both male and female gametes, and a situation is possible when both types of gametes (functional hermaphroditism) or only one type of gametes (afunctional hermaphroditism) have the ability to fertilize.

In synchronous hermaphroditism, an individual is capable of simultaneously producing both male and female gametes.

In the plant world, this situation often leads to self-fertilization, which occurs in many species of fungi, algae and flowering plants (self-fertilization in self-fertile plants).

In the animal world, self-fertilization during synchronous hermaphroditism occurs in helminths, hydras and mollusks, as well as some fish (Rivulus marmoratus), however, in most cases, autogamy is prevented by the structure of the genital organs, in which the transfer of one’s own sperm to the female genital organs of an individual is physically impossible (mollusks, in particular , Aplysia, ciliated worms), or the impossibility of fusion of their own differentiated gametes into a viable zygote (some ascidians).

Accordingly, with exogamous synchronous hermaphroditism, two types of copulatory behavior are observed:

mutual fertilization, in which both copulating individuals act as both males and females (most often among invertebrates, examples include earthworms and grape snails)

sequential fertilization - one of the individuals plays the role of a male, and the other plays the role of a female; mutual fertilization does not occur in this case (for example, in perch fish of the genera Hypoplectrus and Serranus).

In the case of sequential hermaphroditism (dichogamy), an individual sequentially produces male or female gametes, and either sequential activation of male and female gonads occurs, or a change in the phenotype associated with the entire sex. Dichogamy can manifest itself both within one reproductive cycle and throughout the life cycle of an individual, and the reproductive cycle can begin with either the male (protandry) or the female (protogyny).

In plants, as a rule, the first option is common - when flowers form, the anthers and stigmas do not ripen at the same time. Thus, on the one hand, self-pollination is prevented and, on the other hand, due to the non-simultaneous flowering time of various plants in the population, cross-pollination is ensured.

In the case of animals, a change in phenotype most often occurs, that is, a change in sex. A striking example is the many species of fish - representatives of the families wrasse (Labridae), grouper fish (Serranidae), pomacentridae (Pomacentridae), parrot fish (Scaridae), most of which are inhabitants of coral reefs.

Pathological hermaphroditism is observed in all groups of the animal world, including higher vertebrates and humans. Hermaphroditism in humans is a pathology of sexual determination at the genetic or hormonal levels.

There are true and false hermaphroditism:

True (gonadal) hermaphroditism is characterized by the simultaneous presence of male and female genital organs, along with this there are both male and female gonads. In true hermaphroditism, the testicles and ovaries can either be combined into one mixed sex gland or located separately. Secondary sexual characteristics have elements of both sexes: a low timbre of voice, a mixed (bisexual) body type, and more or less developed mammary glands.

The chromosome set (karyotype) in such patients usually corresponds to the female karyotype. In more rare cases, there is a situation where there are both cells containing a female chromosome set and cells containing a male chromosome set (the phenomenon of so-called mosaicism). True hermaphroditism is an extremely rare disease (only about 150 cases are described in the world literature).

Gynandromorphism (ancient Greek γυνή - woman + ἀνήρ, gender ἀνδρός - man + μορφή - type, form) is an anomaly, expressed in the fact that in one organism large areas of the body have the genotype and characteristics of different sexes. It is the result of the presence in male and female cells of the body of sets of sex chromosomes with different numbers of the latter, such as in many insects. Gynandromorphism occurs as a result of incorrect distribution of sex chromosomes among cells during impaired maturation of the egg, its fertilization or fragmentation.

Individuals - gynandromorphs are most pronounced in insects with clearly manifested signs of sexual dimorphism, while the following types of gynandromorphs are morphologically distinguished:

bilateral, in which one longitudinal half of the body has male characteristics, the other female;

anterior-posterior, in which the front part of the body bears the characteristics of one sex, and the back - the other;

mosaic, in which areas of the body interspersed, bearing characteristics of different sexes.

In vertebrates and humans, due to the action of sex hormones, similar phenomena lead to sexual anomalies, in which the sectorial distribution of male and female tissues usually does not appear so sharply.

With intersexuality, a more complex differentiation of female and male characteristics is observed.

Intersexuality is the presence of characteristics of both sexes in a dioecious organism, and these characteristics are not fully developed, intermediate (cf. Hermaphroditism). Characteristics of both sexes appear together on the same parts of the body (cf. gynandromorphism).

The embryonic development of such an organism is called intersex; it begins normally, but from a certain point continues like the other sex. The sooner the direction of development of an organism changes, the more pronounced its intersexuality is.

It is the result of a deviation from the norm in the set of sex chromosomes and genes at the time of fertilization when gametes unite into a zygote. Depending on the nature of the disorder, there can be triploid or another - aneuploid intersexuality. Diploid intersexuality is observed when different geographical races are crossed in the gypsy moth butterfly, either in females or in males, depending on the type of crossing.

Forms of intersexuality, the so-called pseudohermaphroditism in humans, can also be caused by a violation of the normal number of sex chromosomes. Moreover, in Drosophila flies, the determining factor in the development of sex is the ratio of the number of pairs of sex chromosomes and autosomes, so in them intersexuality is usually associated with a violation of this ratio (for example, observed with a ratio of 3A:2X - three sets of autosomes per two sex chromosomes). In humans, the determining factor in the development of male sex is the presence of the Y chromosome, while intersex traits are observed in men with Klinefelter syndrome (XXY set of sex chromosomes).

Hormonal intersexuality. If in animals the secretion of male or female hormones by the gonads determines the development of secondary sexual characteristics, then the phenomenon of hormonal intersexuality can be observed in them.

Ticket 13

1. Provisional organs, types and formation of formations of provisional cells

Provisional organs (German provisorisch - preliminary, temporary) are temporary organs of the embryos or larvae of multicellular animals, functioning only during the embryonic or larval period of development. They can perform functions specific to the embryo or larva, or the main functions of the body before the formation of similar definitive (final) organs characteristic of an adult organism.

Examples of provisional organs: chorion, amnion, yolk sac, allantois and serous membrane and others.

The amnion is a temporary organ that provides an aqueous environment for the development of the embryo. In human embryogenesis, it appears at the second stage of gastrulation, first as a small vesicle, the bottom of which is the primary ectoderm (epiblast) of the embryo

The amniotic membrane forms the wall of the reservoir filled with amniotic fluid, which contains the fetus.

The main function of the amniotic membrane is the production of amniotic fluid, which provides an environment for the developing organism and protects it from mechanical damage. The epithelium of the amnion, facing its cavity, not only secretes amniotic fluid, but also takes part in their reabsorption. The amniotic fluid maintains the required composition and concentration of salts until the end of pregnancy. The amnion also performs a protective function, preventing harmful agents from entering the fetus.

The yolk sac is an organ that stores nutrients (yolk) necessary for the development of the embryo. In humans, it is formed by extra-embryonic endoderm and extra-embryonic mesoderm (mesenchyme). The yolk sac is the first organ in the wall of which blood islands develop, forming the first blood cells and the first blood vessels that transport oxygen and nutrients to the fetus.

Allantois is a small process in the embryo that grows into the amniotic leg. It is a derivative of the yolk sac and consists of the extraembryonic endoderm and the visceral layer of mesoderm. In humans, the allantois does not reach significant development, but its role in ensuring nutrition and respiration of the embryo is still great, since vessels located in the umbilical cord grow along it to the chorion.

The umbilical cord is an elastic cord connecting the embryo (fetus) to the placenta.

Further development of the chorion is associated with two processes - the destruction of the uterine mucosa due to the proteolytic activity of the outer layer and the development of the placenta.

The human placenta (baby place) belongs to the type of discoidal hemochorial villous placenta. The placenta provides a connection between the fetus and the maternal body and creates a barrier between the blood of the mother and the fetus.

Functions of the placenta: respiratory; transport of nutrients, water, electrolytes; excretory; endocrine; participation in myometrial contraction.

Send your good work in the knowledge base is simple. Use the form below

Students, graduate students, young scientists who use the knowledge base in their studies and work will be very grateful to you.

Posted on http://www.allbest.ru/

Introduction
Terminology
3. Classification
4. Abnormalities of sex chromosomes
5. True hermaphroditism
6. Mixed gonadal dysgenesis
Conclusion

Introduction

The birth of children with bisexual genitalia (male and female external genitalia) and intersex (when the sex of the child is not clear upon examination) is a complex problem not only of a medical nature, but also of a social nature, but also a social problem.

The purpose of this essay is to reveal the topic “Hermaphroditism”. To achieve the goal, the following tasks were set: describe the terminology associated with this topic, normal sexual differentiation, note its possible violations, consider the classification of hermaphroditism and analyze all its types, describe the method of histological diagnosis of hermaphroditism.

Terminology

Intersexuality is the presence in a dioecious organism of characteristics of both sexes, and these characteristics are not fully developed, intermediate. Characteristics of both sexes appear together on the same parts of the body.

Hermaphroditism is a congenital disorder of sexual development in which the external genitalia have sexual characteristics of both female and male. Hermaphroditism causes difficulty in classifying an individual as a particular gender. It is a form of intersexism. Occurs on average in one in 2,000 newborns.

There are true and false hermaphroditism. True (gonadal) hermaphroditism is characterized by the simultaneous presence of male and female genital organs, along with this there are both male and female gonads. True hermaphroditism is much less common than false hermaphroditism (about 150 cases are described in the entire world literature). In true hermaphroditism, the testicles and ovaries can either be combined into one mixed sex gland or located separately. Secondary sexual characteristics have elements of both sexes: a low timbre of voice, a mixed (bisexual) body type, and more or less developed mammary glands. The chromosome set (karyotype) in true hermaphroditism usually corresponds to the female karyotype; less often there are cells containing the female chromosome set and cells containing the male chromosome set (the phenomenon of so-called mosaicism).

If the signs of true hermaphroditism extend not only to the gonads, but also to internal sexual characteristics, this is complete true hermaphroditism.

False hermaphroditism (pseudohermaphroditism) occurs when there is a contradiction between the internal (chromosomal and gonadal) and external (structure of the genital organs) characteristics of sex (bisexual development), i.e. the gonads are formed correctly according to the male or female type, but the external genitalia have signs of bisexuality. Endocrine factors and chromosomal mechanisms play a major role in sex differentiation. Disturbances in the relationship between hormones secreted by the adrenal cortex, gonads, pituitary glands of the mother and fetus and the placenta affect the correct formation of the child’s sex during the intrauterine period, which can cause the presence of gonads of one sex and sexual characteristics inherent in the other sex. It is almost impossible to determine gender in pseudohermaphroditism based on the appearance and structure of the external genitalia.

Male pseudohermaphroditism is associated with 46 XY male type, which has dual sexual characteristics or female external genitalia. Abnormalities can vary from simple hypospadias to a full female phenotype. Such disorders are the result of insufficient androgen stimulation of genital development and are most often due to underdevelopment of Leydig cells, defects in testosterone biosynthesis and partial or complete androgen resistance. This can be caused by rare feminizing tumors of the mother’s adrenal cortex, excessive treatment with female sex hormones, etc.

The development in girls of male-type external genitalia and other secondary male sexual characteristics in the presence of ovaries, uterus and tubes determines female false hermaphroditism. It is characterized by a 46 XX karyotype, normal Müllerian duct structures, absence of Wolffian duct structures, and virilization of the external genitalia. It occurs as a result of a tumor of the mother's adrenal cortex, treatment during pregnancy with male hormones and some other hormonal drugs. Male and female hermaphroditism, in turn, are divided into external, internal and complete. In the presence of male gonads and the similarity of the external genital organs with female ones, they speak of external male false hermaphroditism; in the presence of testicles and at the same time the uterus, tubes, underdeveloped prostate gland and seminal vesicles - about internal male false hermaphroditism; a combination of abnormal development of the external and internal genital organs - about complete false hermaphroditism.

1. Normal sexual differentiation

Stages and mechanisms of sexual differentiation. At the moment of fertilization, the genetic sex of the embryo is determined (the set of sex chromosomes in the zygote). Genetic sex determines the formation of gonadal sex (formation of male or female gonads). In turn, the gonadal sex determines the formation of phenotypic sex (the formation of the genital ducts and external genital organs according to the male or female type).

Differentiation of the gonads (formation of the gonadal sex). At the 3rd week of embryogenesis, primary germ cells appear in the wall of the yolk sac - the precursors of oogonia and spermatogonia. At the 4th week, thickenings appear on the medial surfaces of the primary kidneys - sex cords. These are the rudiments of the gonads, consisting of mesenchymal cells of the primary kidney and covered with coelomic epithelium. Initially, the sex cords in male and female embryos do not differ (indifferent gonads).

At the 5th-6th week of embryogenesis, primary germ cells move from the yolk sac to the sex cords. They migrate along the blood vessels and mesenchyme of the hindgut mesentery. From this moment the formation of the gonadal sex begins. Primary germ cells stimulate the proliferation and differentiation of mesenchymal cells and coelomic epithelial cells in the sex cords. As a result, the indifferent sex glands turn into testes or ovaries and are laced from the primary kidneys. Normally, the sex cords differentiate into ovaries if they are populated by primary germ cells with a karyotype of 46, XX, and into testes if they are populated by cells with a karyotype of 46, XY. The transformation of sex cords into testes is determined by the SRY (sex-determining region Y) gene, localized on the Y chromosome. The SRY gene encodes a testicular development factor. This DNA-binding protein induces the transcription of other genes that direct testicular differentiation.

Testicular development. At the 6th-7th week of embryogenesis, the testicular cortex is formed from the coelomic epithelium of the sex cord. Subsequently, the surface layer of cortical cells turns into the tunica albuginea of the testicle. From the inner layer of the cortex, sex cords grow into the mesenchymal stroma of the gland. They consist predominantly of epithelial (somatic) cells, between which lie primary germ cells. The reproductive cords together with the mesenchymal stroma form the testicular medulla. Almost from the very beginning of the growth of the sex cords, the expression of the SRY gene increases in epithelial cells. As a result, the cortex degenerates (only the tunica albuginea remains), and the reproductive cords turn into convoluted seminiferous tubules. The epithelial cells of the reproductive cords differentiate into Sertoli cells, and the mesenchymal cells of the medulla differentiate into Leydig cells. By the 9th week of embryogenesis, Sertoli cells begin to secrete Müllerian duct regression factor, and Leydig cells begin to secrete testosterone. Under the influence of testosterone, primordial germ cells in the convoluted seminiferous tubules differentiate into spermatogonia (this occurs after the 22nd week).

Development of the ovaries. At the 7th week of embryogenesis, the ovaries separate from the primary kidneys. From the coelomic epithelium of the sex cord, short sex cords containing primary germ cells grow deep into the mesenchymal stroma. Primary germ cells multiply and turn into oogonia. By the 5th-6th month of embryogenesis, about 7 million oogonia are formed. About 15% of oogonia turn (without division) into first-order oocytes, and the rest degenerate. Oocytes of the first order enter the 1st division of meiosis, which is blocked at the prophase stage. At the same time, the genital cords are dismembered and primordial follicles are formed. Each primordial follicle contains a first-order oocyte covered with a single layer of epithelial cells. Then the maturation of the follicles begins: a transparent membrane forms around the oocyte; epithelial cells grow and form a multilayer epithelium - granular layer. Subsequently, the follicle develops an outer shell formed by mesenchymal cells and dense connective tissue. Meiotic division of the first order oocyte is resumed only in mature (preovulatory) follicles under the influence of LH. At the 17th-20th week of embryogenesis, the structure of the ovaries is finally formed. Follicles at different stages of maturation form the ovarian cortex. A newborn girl has about 1 million follicles. Some follicles undergo atresia, so that by the time menarche occurs, 400,000 follicles remain in the ovaries. The medulla consists of connective tissue that contains blood vessels and nerves.

It is likely that other, as yet unknown factors also influence the differentiation of the gonads.

2. Development of the reproductive ducts. By the 4th week of embryogenesis, paired Wolffian (mesonephric) ducts are formed next to the sex cords from the mesoderm, and by the 5th week, Müllerian (paramesonephric) ducts are formed lateral to them.

Differentiation of Wolffian ducts. If a normal testicle is located next to the Wolffian duct, then between the 9th and 14th weeks the epididymis, vas deferens, seminal vesicle and ejaculatory duct are formed from this duct. Differentiation of the Wolffian duct is stimulated by testosterone secreted by Leydig cells. Testosterone does not diffuse to the opposite side of the embryo and therefore acts only on the Wolffian duct closest to the testicle. If there is an ovary near the Wolffian duct or if the testicle does not secrete testosterone, this duct degenerates.

Differentiation of Müllerian ducts. If there is a normal testicle next to the Müllerian duct, then this duct degenerates at the 9th-10th week of embryogenesis. Degeneration is caused by the Müllerian duct regression factor, a glycoprotein secreted by Sertoli cells. If the production or action of the Müllerian duct regression factor is impaired, or if there is an ovary adjacent to the Müllerian duct, then the fallopian tube, half of the uterine body (which later fuses with the opposite half), and the upper two-thirds of the vagina are formed from this duct. The ovaries do not participate in the differentiation of the Müllerian ducts, therefore, with ovarian dysgenesis, the formation of derivatives of these ducts is not impaired.

3. Development of the external genitalia. The phenotypic sex of a newborn is determined precisely by the external genitalia. Their development occurs simultaneously with the development of the urinary tract and distal gastrointestinal tract.

By the 3rd week of embryogenesis, a cloacal membrane is formed, covering the hindgut. An unpaired genital tubercle is formed in front of it, and two genital folds are formed laterally. By the 6th week, the cloacal membrane is divided into the urogenital and anal membranes, and by the 8th week it becomes the urogenital groove in the front and the anal-rectal canal in the back. The genital folds are divided into 2 pairs of folds: the genitourinary folds, located medially and surrounding the genitourinary groove, and the labioscrotal folds, located laterally. All these events occur before the formation of the gonads and are not regulated by hormones. Differences in male and female external genitalia appear after the 8th week of embryogenesis. The direction of development of the external genitalia is determined by sex hormones, primarily testosterone.

In the male fetus, testosterone produced in the testicles reaches the genital tubercle through the blood, where it is converted by the enzyme 5-alpha reductase into dihydrotestosterone. This hormone acts on androgen receptors and causes rapid growth of the genital tubercle. The urogenital groove moves forward, its edges (urogenital folds) grow together and by the 12th week the spongy part of the urethra is formed. The labioscrotal folds fuse caudally to form the scrotum. The formation of the spongy part of the urethra ends by the 4th month of embryogenesis, when the ectoderm of the penis invaginates into the lumen of the urethra.

In a female fetus, testosterone levels in the blood are normally very low. Therefore, the indifferent external genitalia, formed by the 8th week of embryogenesis, subsequently undergo only minor changes. The genital tubercle turns into the clitoris, which can increase under the influence of androgens not only in the prenatal period, but also after birth. The genitourinary folds remain in the same place and form the labia minora. The labial-scrotal folds increase without moving and become the labia majora, while the urogenital groove remains open, forming the vestibule of the vagina. The position of the external opening of the urethra is determined by the 14th week of embryogenesis. At later stages of embryogenesis, androgens are no longer able to cause fusion of the labial-scrotal folds and forward displacement of the urogenital folds.

2. Possible disorders of sexual differentiation

The main sign of disorders of sexual differentiation is the external genitalia of an intermediate type in newborns. Such newborns require urgent evaluation and constant monitoring, as they may develop a salt crisis and shock. It is necessary to find out the cause of the abnormality of the genital organs as quickly as possible, reassure and reassure the parents, and together with them choose for the child the gender of upbringing that best matches the structure and function of the genital organs.

Sexual differentiation can be disrupted at any stage of sex differentiation. Disorders can be caused by aberrations of sex chromosomes, mutations of genes involved in the development of gonadal and phenotypic sex, as well as non-genetic causes (for example, taking virilizing drugs during pregnancy). Genetic sex depends on the karyotype of the zygote. Karyotype 46,XX corresponds to the female sex, and 46,XY to the male sex. Causes of genetic sex disorders:

1. Changes in the number or structure of sex chromosomes. For example, the classic variants of Klinefelter syndrome (karyotype 47,XXY) and Turner syndrome (karyotype 45,X) are caused by non-disjunction of sex chromosomes in meiosis during gametogenesis. Turner syndrome can also be caused by a deletion of one of the X chromosomes.

2. Mosaicism on sex chromosomes (XX/XY). Such mosaicism is found in a third of patients with true hermaphroditism.

3. Point mutations of genes on sex chromosomes, for example, mutations of the SRY gene on the Y chromosome.

Gonadal sex disorders

1. Differentiation of the gonads on the right and left occurs independently. Therefore, their histological structure may vary. Moreover, different sex glands can simultaneously form in the same sex cord. For example, true hermaphrodites have a testicle and an ovary on both sides in the form of a single formation (ovotestis), or there is a testicle on one side and an ovary on the other.

2. Normally, testicular development is determined by the SRY gene, localized on the Y chromosome. However, this gene is found in some gonadal and phenotypically male patients who do not have a Y chromosome. It is likely that in such cases the SRY gene is transferred to the X chromosome or to an autosome as a result of translocation. Testicles can also form in patients with karyotype 46.XX who do not have the SRY gene. It is assumed that such patients have mutant genes that direct the differentiation of the sex cords into the testes, and not into the ovaries.

3. At the stage of migration of primary germ cells into the sex cords, the following anomalies may occur:

The karyotypes of primary germ cells and somatic cells of the sex cords do not match (for example, a 46,XX cell migrates into a sex cord formed by 46,XY cells). Primary germ cells usually die, and a “sterile” testicle is formed, containing no germ cells. However, there are cases when the primordial germ cells survive. Then the testicle contains only germ cells with a karyotype of 46,XX.

The reverse is also possible. Primary 46,XY germ cells can induce genes that direct the differentiation of somatic 46,XX cells in the sex cords toward testis formation.

4. Unlike the testicle, the ovaries can dedifferentiate and turn into connective tissue cord-like formations. Possible causes of ovarian dedifferentiation:

Oogonia do not form first order oocytes.

First order oocytes are not capable of meiotic division (for example, due to aneuploidy or chromosomal aberrations). This is probably how cord-like gonads develop in girls with Turner syndrome (karyotypes 45.X or 46.X).

Follicles do not form around the oocytes.

Thus, for the development of the ovary, not only the presence of normal X chromosomes in the sex cord cells is necessary, but also the presence of normal first-order oocytes.

5. Disorders during the development of the external genitalia lead to atresia of the anus, exstrophy of the bladder or the formation of a congenital cloaca, transposition of the penis and scrotum (when the genital tubercle forms caudal to the genital folds) and agenesis of the penis. Such anomalies are usually caused by disorders of the early stages of embryogenesis, and not by disorders of genetic and gonadal sex or the secretion of sex hormones.

6. At the same stage, the process of intussusception of the penis into the lumen of the urethra is disrupted by insufficiency of testosterone and dihydrotestosterone or an excess of androgen antagonists (progesterone).

3. Classification

1. Sex chromosome disorders:

A) true hermaphroditism;

B) violations of the formation of sex chromosomes and corresponding mosaics;

B) atypical or mixed gonadal dysgenesis.

2. Male pseudohermaphroditism (MPH):

A) gonadal dysgenesis, agonadism;

B) testicular feminization;

B) incomplete testicular feminization;

D) defects in testosterone biosynthesis;

D) persistence of oviduct.

3. Female pseudohermaphroditism (FPG):

A) defects in steroid synthesis;

B) tumors in the mother that produce androgens;

B) exogenous influences (medicines).

The first diagnostic step for clearly intersex genitalia is chromosomal analysis, since sex chromosome aberrations are quantitatively predominant in the genesis of genital anomalies. In most cases, this allows the observation to be assigned to a specific group. In fact, 50% of patients with true hermaphroditism have a pure 46-XX karyotype in lymphocyte culture, 80% are chromatin-positive.

With a purely male karyotype in combination with intersex or female genitalia, they speak with some caution about male pseudohermaphroditism. Patients with a purely female chromosome set and incomplete or completely male genitalia are classified as female pseudohermaphroditism. If, with normal sex chromosomes, in addition to genital abnormalities, there are somatic deformities, after excluding endocrine causes, the presence of a familial or sporadic syndrome of unknown origin can be assumed.

However, recently this classification has ceased to satisfy both patients and doctors. On the one hand, the active use of the term “hermaphroditism” has led to a violation of the confidentiality of the patient’s illness and frequent misinterpretations in the patient’s environment. The birth of a child with an abnormal structure of the external genitalia is a difficult psychological test for the baby’s family, inevitably entails social problems for relatives, and the existing terminology for this condition (hermaphrodite) only aggravates the psychological discomfort in the family. On the other hand, after the mechanisms of certain diseases have been accurately established and modern diagnostic capabilities make it possible to establish a nosological diagnosis, there is a need to change the classification to reflect a more complete reflection of the nature of the condition that has arisen. It is proposed to replace both the term “hermaphroditism” itself, which sounds offensive to patients, and the indication of gender in the diagnosis, i.e. male or female hermaphroditism. It is recommended to use the term “disturbance of sex development” (DSD). See table on slide.

In the future, for the convenience of understanding the problem, we will resort to more established terminology.

4. Abnormalities of sex chromosomes

The condition of altered genitalia in Turner syndrome and Klinefelter syndrome cannot be considered intersex. Possible hypoplasia of the labia minora and hypoplasia of male genitalia with small testicles in adults in childhood are not so noticeable as to raise doubts when establishing somatic sex based on examination of the external genitalia. With other karyotypes this (in particular, at birth) also does not cause difficulties.

If there is a mosaic pattern of sex chromosomes, anomalies of the external genitalia actually develop, mainly clitoral hypertrophy, as well as partial fusion of the labia minora and labia majora, which makes primary sex determination impossible.

5. True hermaphroditism

The diagnosis of true hermaphroditism can be assumed if patients have dual or indeterminate genitalia. The diagnosis can be finally confirmed only after laparotomy and histological examination of the internal genital organs. It is necessary to differentiate true hermaphroditism from false male hermaphroditism, in which there is testicular tissue, but no ovaries, and false female hermaphroditism, caused by virilizing hyperplasia of the adrenal cortex, characterized by a sharply increased excretion of 17-ketosteroids.

The development of the genital organs depends on the predominance of the female or male gonad, their development and functional activity. There are several combinations of testicular and ovarian tissue. So, on one side there may be a testicle, and on the other, an ovary; the genitals can be represented on both sides by formations that are anatomically a combination of testicular and ovarian tissue - ovotestis; in the presence of a testicle or ovary on one side, an ovotestis may be located on the other side and, finally, an ovotestis may exist on one side in the absence of gonadal tissue on the other.

The degree of development of testicular and ovarian tissue varies significantly until the appearance of mature follicles in the ovaries and the initial stages of spermatogenesis in the testes. It has been established that testicular tissue, presented in the form of a testicle, has a more pronounced androgenic effect compared to ovotestis. Thus, in the majority of patients at birth, the female gender was determined based on the presence of ovotestis. Externally, patients may have a small penis, hypospadias, and scrotolabial folds similar in shape to the scrotum, which contains a testicle or resembles the labia in the absence of gonads. The vagina is often well developed, can open into the posterior urethra, the clitoris is hypertrophied, which gives the genitals a feminine appearance. In a number of patients, in the presence of a penis, periodic bleeding from the vagina or urethra (if there is a urogenital sinus) may occur; spermatozoa are sometimes found in the semen. Urinary excretion of estrogens and androgens is between the male and female norms.

6. Mixed gonadal dysgenesis

A form of intersexism in which, on the one hand, a dysgenetic gonad is detected - gonad-cord, on the other - a testicle or gonadal tumor. In most cases, the development of the paramesonephric ducts is only partially delayed. In some observations, derivatives of the mesonephric ducts (for example, the vas deferens) are preserved due to the pronounced effect of fetal testosterone. Symptoms. The external genitalia are formed very differently. Due to only unilateral testicular descent or the presence of tubal and uterine components, the formation of the genital fold (labia majora or halves of the scrotum) may be asymmetrical. General symptoms such as short stature and other optional signs in some cases suggest the presence of Turner syndrome.

7. Male pseudohermaphroditism

Undoubted male karyotype and bilateral testicular anlage (the exception is agonadism), the absence of structural derivatives of the paramesonephric ducts (the exception is the oviduct persistence syndrome, the attribution of which to male pseudohermaphroditism is controversial). Reasons: decreased or absent testosterone production, as well as ineffective testosterone action on target organ cells with normal levels of androgen secretion. Depending on the degree of disturbance, the spectrum of anomalies of the external genitalia ranges from normal female (with a shortened, blindly ending vagina without a cervix) to almost normal male with hypospadias or cryptorchidism.

Agonadism. We are talking about a rare, often familial, disease. Patients have a karyotype of 46, XY, normal female or slightly virilized (I - II degree according to Prader) genitalia without the uterus and tubes; in some cases, remnants of mesonephric ducts are found. Gonads may not be anatomically visible. However, judging by the fact that there are signs of the influence of AMH (factor X), testicular tissue or Sertoli cells must exist in the embryonic period. The authors believe that failure to detect testes at laparotomy is not sufficient for the diagnosis of agonadism. They suggest that between actual agonadism and "anorchia" with normal male genitalia, there is a spectrum of abnormalities of the external genitalia depending on the amount of testosterone-producing tissue.

Testicular feminization. In most cases, testicular feminization is diagnosed during puberty.

Definition. Male pseudohermaphroditism with karyotype 46, XY, testes, normal female external genitalia (complete form) or intersex genitalia (incomplete form) due to resistance of peripheral tissues (target organs) to testosterone and 5alpha-dihydrotestosterone produced in normal quantities.

Genetics. Familial cases are common. Inheritance on the X chromosome, recessive type. Complete and incomplete forms do not occur simultaneously in the same family.

The prevalence is unknown, as there are significant difficulties in diagnosing incomplete forms. For the full forms, the prevalence is estimated to be 1:60,000; in reality it is obviously larger.

Defects in testosterone biosynthesis. While defects in 21- and 11-hydroxylases lead to female pseudohermaphroditism due to increased intrauterine androgenization, there are a number of disorders that interfere with the synthesis of testosterone already in the prenatal period. These defects, up to and including 20,22-desmolase deficiency, are never so complete that normal female genitalia are formed: in most cases with a male karyotype and normal testes, the uterus and upper part of the vagina are absent, and the intersex external genitalia are clearly virilized. Hypospadias of varying degrees are especially characteristic in both undescended and normally localized testicles.

Persistence of oviduct. We are talking about phenotypically normal men who often have a violation of testicular descent, although otherwise the external genitalia are unremarkable. If such diseases have not been encountered in the family, then in most cases the diagnosis is made during surgery for a hernia or cryptorchidism. In this case, a hypoplastic uterus with tube rudiments is found (for example, in the hernial sac). It is believed that the cause of the disease is a deficiency of anti-Mullerian hormone (AMH, factor X) or resistance of the paramesonephric ducts to it.

8. Female pseudohermaphroditism

Intrauterine virilization of a fetus of female genetic and gonadal sex can be a consequence of three known reasons:

a) intrauterine virilization due to the production of androgens by the adrenal glands due to defects in the synthesis of steroids (adrenogenital syndrome);

b) endogenous production of androgens in the mother’s body;

c) administering hormones or other medications to the mother.

Female pseudohermaphroditism due to defects in steroid synthesis. We are talking about: a) 21-hydroxylase defect without and with salt wasting syndrome; b) 11-hydroxylase defect; c) a dehydrogenase defect, in which mild virilization of a genetically female fetus is detected. Insufficient production of mineralo- and glucocorticoids comes to the fore in the clinical picture.

Female pseudohermaphroditism due to androgen-producing tumors of the ovaries or adrenal cortex in the mother. In most cases, maternal virilization is noticeable already during pregnancy. Female pseudohermaphroditism resulting from exposure to hormones or other drugs during pregnancy. Taking hormones or other drugs by the mother during pregnancy may cause virilization of the fetus. Female pseudohermaphroditism in a child whose mother experienced transient symptoms during pregnancy indicating androgenic influences.

9. Histological diagnosis

An indispensable condition for examining a hermaphrodite is a histological examination of the tissue of both gonads obtained from their biopsy. The condition of the right and left gonads may be different, so a biopsy of one of them does not give an idea of the structure of both gonads

When the gonads are located in the abdominal cavity, obtaining biopsy material is possible using laparoscopy and laparotomy; laparotomy is more preferable: this allows for a broader examination of the gonads and pelvic organs and at the same time performing the necessary surgical interventions.

When examining the gonads, the functional state and degree of maturity of all morphological structures are assessed: gonocytes, seminiferous tubules, follicles and interstitial tissue (Leydig cells, theca tissue). This helps to predict the potential functionality of the gonad and make a decision on the choice of sex of the hermaphrodite.

sexual differentiation hermaphroditism chromosome

Conclusion

The topic of hermaphroditism is relevant in our time, because represents not only a medical, but also a huge social problem for the people themselves suffering from this disease, for their immediate environment.

The capabilities of modern medicine allow this group of patients to live a full life and, in some cases, allow them to have children. However, this problem is completely beyond the control of modern medicine. There are a great many causes of hermaphroditism, but there are very few methods to correct it, with the exception of some forms. Manifestations of hermaphroditism are diverse, and it cannot always be detected immediately. With hermaphroditism, a person experiences difficulties with sexual self-determination in a social environment.

Histological diagnosis (gonadal biopsy) allows one to assess the functional and morphological state of the gonads and is one of the main methods for making this diagnosis. The task of medicine is to develop effective methods for diagnosing hermaphroditism, which make it possible to say with a high degree of probability about the diagnosis of a child, and to develop methods for correcting and treating hermaphroditism in humans, returning a person to the opportunity to have children.

Posted on Allbest.ru

...

Similar documents

The manifestation of hermaphroditism in humans is the presence of male and female sexual characteristics together. Analysis of true and false hermaphroditism. The essence of sexual dimorphism, gonadal dysgenesis syndrome, incomplete masculinization. Methods for treating hermaphroditism.

test, added 03/28/2012

The main clinical signs of congenital pathology. Premature sexual development. True (gonadal) hermaphroditism. Etiology and clinical picture. Causes and pathogenesis of cryptorchidism, complications and prognosis. Adrenogenital syndrome in girls.

presentation, added 04/07/2015

Definition of Shereshevsky-Turner syndrome (gonadal dysgenesis). Consideration of the clinical picture of a disorder of the development of the gonads caused by an abnormality of the sex chromosomes. Treatment with female sex hormones. Causes and development of Klinefelter syndrome.

presentation, added 06/01/2015

Turner syndrome as a genetically determined form of primary agenesis or dysgenesis of the gonads. The incidence of the disease among newborns and complications during pregnancy. Pathogenesis of disorders of the formation of the gonads, diagnosis and treatment methods.

test, added 12/27/2010

Classification of abnormal development of the genital organs. Adrenogenital syndrome - diagnosis and treatment. Anomalies of ovarian development. Gonadal dysgenesis. Sclerocystic ovary syndrome - hormonal and drug therapy. Incorrect positions of the uterus.

presentation, added 06/23/2012

Factors of developmental disorders of the gonads in the early period of embryonic development caused by an abnormality of sex chromosomes. Clinical symptoms of Shereevsky-Turner. Methods of treating patients with this disease, methods of diagnosis and examination.

presentation, added 10/21/2013

The concept of hereditary diseases: changes in the number or structure of chromosomes. Classification of chromosomal disorders caused by changes in sex and non-sex chromosomes. Basic types of heredity. Metabolic diseases and immune disorders.

presentation, added 11/21/2010

Development of the male reproductive system and external genitalia. The process of testicle formation. Malformations of the seminal vesicle and prostate gland. Abnormalities of the urethra. The reasons for untimely descent of the testicle are its hypoplasia and dysplasia.

abstract, added 01/19/2015

Syndromes, the development of which is caused by changes in the number or structure of chromosomes. Frequency of chromosomal diseases among newborns. Down syndrome, Patau syndrome, Edwards syndrome. Anomalies of the combination of sex chromosomes. Partial monosomy syndromes.

presentation, added 01/06/2013

Gonadal, extragonadal and extrafetal congenital forms of disorders of sexual development. Chromosomal pathology. Shereshevsky-Turner syndrome and “pure” gonadal agenesis. X-chromosome segregation disorders. Klinefelter's syndrome, incomplete masculinization.

What are the advantages of hermaphroditism and the features of dioeciousness?

Hermaphroditism exists, because in some cases it is observed. Low population density

Dioecy is advantageous in that homozygotization of mutations does not occur, therefore there are fewer fatalities during reproduction. The genetic variability of the population is increasing.

Aromorphoses of plants and animals that contribute to the conquest of land:

Plants: Integumentary tissues (epidermis, cork), conductive tissues, mechanical tissues, sexual process independent of drip-liquid water,

Animals: the appearance of lungs, first wet, then dry and hard body coverings, the development of sensory organs adapted to terrestrial conditions (vision), reproduction, independent of water, improvement of the excretory system (excretion products became completely different due to lack of water) .

Seminar No. 6

Elementary concepts of the synthetic theory of emission.

1. Basic properties of living matter on our planet.

It is necessary to have a general understanding of the object of evolution, the basic properties of living things. Separately, such properties as metabolism, mobility, irritability, growth, reproduction, adaptability are also found among inanimate nature, and therefore cannot be considered as specific properties of the living.

Five axioms of theoretical biology. In one of the last and most successful attempts, living things are characterized by the following features, formulated by B. M. Mednikov (1982) in the form of axioms of theoretical biology:

1) All living organisms turn out to be a unity of a phenotype and a program for its construction (geno-type), transmitted by inheritance from generation to generation (A. Weisman’s axiom).

2) The genetic program is formed in a matrix way. The gene of the previous generation is used as a matrix on which the gene of the future generation is built (N.K. Koltsov’s axiom).

3) In the process of transmission from generation to generation, genetic programs, as a result of various reasons, change randomly and undirectedly, and only by chance such changes can be successful in a given environment (1st axiom of Ch.D.a).

4) Random changes in genetic programs during the formation of a phenotype are amplified many times over (the axiom of N.V. Timofeev-Resovsky).

5) Repeatedly enhanced changes in genetic programs are subject to selection by environmental conditions (2nd axiom of Charles Darwin).

Nekot. properties that are directly related to the process of evolutionary development occurring everywhere.

Discreteness and integrity are two fundamental properties of the organization of life on Earth.

Living objects in nature are relatively isolated from each other (individuals, populations, species). Any individual multicellular animal consists of cells, and any cell and unicellular creatures consist of certain organelles. Organelles consist of discrete, usually high-molecular, organic substances. in turn, they consist of discrete atoms, elementary (also discrete!) particles. At the same time, a complex organization is unthinkable without the interaction of its parts and structures - without integrity. The integrity of biological systems is qualitatively different from the integrity of the nonliving, and primarily in that the integrity of the living is maintained in the process of development. They are characterized by negative entropy. It is likely that living things exhibit the ability to self-organize matter.

Convariant reduplication ( self-reproduction with changes), carried out on the basis of the matrix principle (the sum of the first three axioms), is apparently the only property specific to life (in the form of its existence known to us on Earth). It is based on the unique ability for self-reproduction of the main control systems (DNA, chromosomes and genes). When control systems self-reproduce in living organisms, it is not mechanical repetition that occurs, but reproduction with the introduction of changes.

2. Levels of life organization on the ground. What evolutionary events occur at each level of the organization.

If we try to identify the main levels that reflect not so much the levels of study, but rather the levels of organization of life on Earth, then the main criteria for such identification should be the presence of specific elementary, discrete structures and elementary phenomena is recognized. (N.V. Timofeev-Resovsky and others were singled out).

Molecular genetic level. The elementary units at this level are the basic control systems (DNA, chromosomes and genes). The main elementary phenomena associated with them can be considered their ability to undergo convariant reduplication, local structural changes (mutations) and the ability to transmit information stored in them to intracellular control systems.

Ontogenetic level. First we need to define the concept of “individual”. An individual (individual, individual) is an elementary indivisible unit of life on Earth. (In some cases, the question of determining the boundaries of an individual is not so obvious, for example, for colonies of polyps and lichens). From an evolutionary point of view, an individual should be considered all morphophysiological units originating from one zygote, gametes, spores, buds, and individually subject to the action of elementary evolutionary factors.

At the ontogenetic level, the unit of life is the individual from the moment of its origin until death. Ontogenesis is the process of unfolding, implementing hereditary information encoded in the control structures of the germ cell. At the ontogenetic level, not only the implementation of hereditary information occurs, but also its testing by checking the consistency in the implementation of hereditary characteristics and the operation of control systems in time and space within the individual. Through the assessment of the individual in the process of natural selection, the viability of a given genotype is tested. Ontogenesis arose after the addition of convariant reduplication by new stages of development. In the course of evolution, the path from genotype to phenotype, from gene to trait, arises and gradually becomes more complicated.

Elementary structures at the ontogenetic level of life organization are cells, and elementary phenomena are some processes associated with differentiation.

Population-species level. The unification of individuals into a population, and populations into species according to the degree of genetic and ecological unity, leads to the emergence of new properties and features in living nature, different from the properties of the molecular genetic and ontogenetic levels.

A population is an elementary structure at the population-species level, and an elementary phenomenon at this level is a change in the genotypic composition of the population; the elementary material at this level is mutations. Elementary factors operating at this level are identified: mutation process, population waves, isolation and natural selection. Each of these factors can exert one or another “pressure”.

Populations are elementary units, and species are qualitative stages of the process of evolution. In general, at the population-species level, the process of evolution actually takes place over generations.

The specific environment for the process of evolution occurring in individual populations is biogeocenosis. At the same time, bio-geocenosis is an elementary unit of the next level of organization of life on Earth.

Biogeocenotic (ecosystem) level. An ecosystem is a “dimensionless” concept, but there is one class of ecosystems that has a certain size and is of fundamental importance as the “building blocks” of the organization of the entire biosphere - biogeocenoses. Biogeocenosis is an ecosystem within which there are no biocenotic, microclimatic, soil and hydrological boundaries. Biogeocenosis is one of the most complex natural systems. Biogeocenoses are an environment for the evolution of their constituent populations. Evolutionary processes also occur at this level; the population composition of the biogeocenosis may change.

3. Macroevolution. Evolutionary process in the horse family.

Macroevolution is a process that takes place over a long period of time, covering vast territories and leading to the formation of new taxonomic groups.

Genus, family, order, class, phylum and kingdom represent realities of a completely different quality than species. The integrity of taxa of the highest ranks is determined not by the genetic integration of their individual constituent units (populations), as is observed within a species, but by the unity of the “structural plan”, based on a common origin.

The evolutionary process occurs in both time and space. Either the conditions for the existence of the species in the territory it occupies change, or the changes in conditions are associated with its colonization of new territories.

A classic example is the history of speciation in the horse family (V.O. Kovalevsky). It shows the close dependence of the historical development of this group of animals on environmental changes.

The horse family is characterized by the following characteristics: the eye sockets are entirely delimited by bones; teeth with a very high crown; their chewing surface is covered with folded enamel; the ulna and radius are fused, and the fibula is reduced; both pairs of limbs are single-fingered, only the third finger is developed.

As V. O. Kovalevsky showed, the modern one-toed horse developed from a form that had a five-toed limb. The ancestors of the horse family were Phenacodus, who lived in the Paleocene. These are relatively small animals with a long tail and five-fingered limbs ending in small hooves. They were semi-digital forms, that is, when walking they touched the ground with the lower surface of their phalanges. Fe-nakodus had teeth with long roots and a low crown, equipped with tubercles along the upper surface. The presence of tuberous teeth indicates that fenacodus were omnivores.

Their descendant, the oldest representative of the horse family Eohippus, lived in the lower Eocene. It was a small animal, about the size of a fox, with a head in which the eye socket was not delimited at the back by bones. In his molars, there was a deviation from the tuberculate type, since V-shaped folds of enamel appeared on them, which indicates the consumption of predominantly plant foods. The ulna and radius were divided again, but a reduction in the marginal rays of the limbs had already begun: the forelimbs had four fingers, and the hind limbs only three. Lived in the tropical forests of North America and ate succulent vegetation. From Eohippus came the closely related Orohippus, which differed only in some changes in the structure of the teeth.

At the end of the Eocene, the nature of vegetation began to change: cereals became widespread. By the Miocene, the hot and humid climate gives way to dry and temperate. In the ancestors of the horse, selection in new conditions contributed to the formation of a number of adaptations to feeding on new food (the teeth, jaw, chewing muscles, and digestive organs changed). The structure of the organs of movement changed, which helped to escape from steppe predators. The animal's body increased.

Already the Oligocene mesohippus was the size of a sheep. In this form, the orbit at the back was also not yet delimited by bones; all four limbs were three-fingered. At the same time, the third finger received the greatest development. The herbivorous type of teeth in Mesohippus was more pronounced than in previous forms.

Starting from the Miocene, a strong divergent process has been going on, leading to the formation of a large number of lateral branches that branched off from the main trunk of the phylogenetic tree of horses. In the Miocene merigippus, the radius and ulna bones began to fuse, much like in a modern horse. The marginal fingers had already become so short that when running the animal used only one third finger.

In the Pliocene, one of the closest ancestors of the modern horse, the three-toed Pliohyppus, the size of a donkey, moved to Europe along with other North American emigrants. From him came the race of horses, cats. widespread throughout Eurasia and both Americas. In the Quaternary period, American horse species became extinct, while a number of steppe and desert species were formed in Eurasia.

As a result of such a long historical process of development, a specific form of animal arose, leading a gregarious lifestyle and grazing in vast open spaces. In connection with living in these conditions, she developed a number of characteristic adaptations, which, in addition to feeding on herbaceous food and speed of movement, also include a long pregnancy and the birth of cubs, capable of following the mother soon after birth.

The process of formation of allopatric species, usually associated with a change in the range of the original species. These changes can be of a twofold nature: either the species expands its range, occupying a new territory, or the range is dismembered under the influence of the emergence of physical barriers, which leads to the isolation of individual populations. In both cases, the path to the formation of a new species lies through the emergence of new subspecies.

4. Microevolution. The nature of the microevolutionary process using the example of tits, gulls, and salamanders.

Microevolution is a process that occurs within a population and leads to differentiation of the species - the disintegration of the species into intraspecific groups of various ranks. In the modern sense, the term “microevolution” was first proposed by Dobzhansky (1937) and Timofeev-Resovsky (1938).

The great tit in the Pleistocene was divided into three groups: the great tit itself, the Bukhara tit and the so-called small tit. The first is distinguished by its largest size, green back and yellow belly. Bukhara tits are medium in size, the color of the back and belly is gray. “Lesser” tits are the smallest, with a yellow back. After the ice retreated, these groups met again, and their relationships changed. The Bukhara group freely interbred with the other two, while at the same time the “small” and actually large, when meeting, behave like different species, without interbreeding with each other.

These “species” are the final links of a single chain of subspecies, interconnected by zones of integration. For such forms, cat. are on the border between subspecies and species, E. Mayr introduced the term “semispecies”.

Apparently, this phenomenon is widespread in nature.

Seagulls. In Western Europe, two forms of gulls live together (the herring gull and the black-billed gull), the cat. were classified as independent species. They exist in the same territory, but do not interbreed. At the same time, these forms are united by a number of subspecies, forming a continuous ring around the Arctic Ocean. In a complex chain of subspecies, these two co-living forms represent typical semi-species.

Salamanders. In the North American salamander Ensatina eschscholtzi, the habitat resembles an ellipse, along the periphery of which there are mountain ranges framing its central desert lowland part. The salamander lives in the mountainous part of its range. The species is divided into a number of geographical races, clearly distinguishable by color. Subspecies living nearby have transitions. But in Southern California the form eschscholtzi lives together with croceater and klauberi, without interbreeding with them. Therefore these three forms are semi-species.

The isolation of a new species will occur when the action of isolating mechanisms spreads to all other populations of this species. In other words, semi-species are species in the process of becoming, “emerging species”.

5. The elementary unit of the evolutionary process. Species and individual. Basic properties of a population.

The evolutionary unit must satisfy the following conditions:

Must appear in time and space as a unity

Must be hereditary

Must really and concretely exist

A population is the smallest self-reproducing group of individuals of the same species, inhabiting a certain space for an evolutionarily long time, forming an independent genetic system and forming its own ecological niche.

The species also has some unity, but the population is the smallest.

The individual is smaller, but does not have its own “evolutionary destiny” in a series of generations.

The main ecological characteristics of the population are size, area, age and sex structure, as well as population dynamics.

The population has a specific area. Individuals outside this range leave the population. The population's range can expand, but to do this, the population must master this new space. The size of the population area largely depends on the degree of mobility of individuals - “the radii of individual or, more precisely, reproductive activity” (Timofeev-Resovsky). In many other cases, the trophic area does not coincide with the reproductive area (from an evolutionary-genetic point of view, we are primarily interested in the reproductive area).

Related to questions about the size of populations is the problem of minimum numbers. The minimum number is the number below which the population inevitably disappears for various ecological and genetic reasons. The population size, like other population characteristics, varies. In each specific case, the minimum population size will be specific to different species.

Dynamics. Population sizes (spatial and number of individuals) are subject to constant fluctuations. The reasons for the dynamics of populations in space and time are extremely diverse and in general terms come down to the influence of biotic and abiotic factors.

Sex composition of the population. It is known that the genetic mechanism of sex determination ensures that the offspring are separated by sex in a ratio of 1:1 (primary sex ratio). Due to the unequal viability of the male and female organism (different viability, undoubtedly an evolutionarily developed trait), this primary ratio is sometimes noticeably different from the secondary one (typical during childbirth in mammals) and even more noticeably different from the tertiary one - characteristic nogo for adults.

6. Population is the smallest chorogenetic unit of evolution. Types of population areas. Population as a chorogenetic unit.

Khoros – space, place, area. … …

Nekot. species have a dual range: trophic and reproductive.

Pink gulls nest in the wet tundra of northeastern Siberian rivers. The trophic range has not been determined.

The river eel spends most of its time in the fresh waters of the rivers of the Black, Azov and other seas and lakes. To reproduce, migrates to sea water (300-400 m, +7˚С). The fry then migrate to rivers.

7. Isolation as a factor of emission. Geographical. Various types of biological isolation.

Isolation is the emergence of any barriers limiting panmixia. The significance of isolation in the process of evolution comes down to the disruption of free crossing, which leads to an increase and consolidation of differences between populations and individual parts of the entire population of the species. Without such consolidation of evolutionary differences, no form formation is possible. In nature there are: spatial and biological isolation.

Spatial isolation can exist in different forms: water barriers separate the population of “land” species, and land barriers isolate the population of aquatic species, hills isolate lowland populations, and plains isolate mountain populations, etc. The emergence of territorial isolation mechanical isolation is explained by the history of the development of species in certain territories. In certain cases, the main cause of isolation was the advance of glaciers. Spatial isolation within a species exists in two of its manifestations: isolation by any barriers between parts of the species population and isolation determined by the greater possibility of mating of closely living individuals, i.e. isolation by distance.

Biological isolation is provided by two groups of mechanisms: those eliminating crossing (pre-copulatory) and isolation during crossing (post-copulatory).

Mating of closely related forms is hampered by differences during sexual activity and maturation of reproductive products. In nature, biotopic isolation is common, in which potential mating partners do not meet, since they often live in different places. Thus, some finches (Fringilla coelebs) nest in the Moscow region in taiga-type forests, and others in low and sparse stands with a large number of clearings. The potential for cross-mating of individuals of these groups is somewhat limited. An interesting example of biotopic isolation is sympatric intraspecific forms in the common cuckoo (Cuculus canorus). Europe is home to several “biological races” of cuckoos, differing in the genetically determined color of their eggs. In Eastern Europe, some lay blue eggs in the nests of the common redstart and stonechat, others lay light speckled eggs in the nests of small passerine birds that have eggs of a similar color. Isolation between these forms of cuckoos is maintained by the destruction of insufficiently camouflaged eggs by host species. In many species, biotope preference is an effective isolation mechanism.

Of great importance in the emergence and maintenance of biological isolation in closely related forms is ethological isolation - complications of mating caused by behavioral characteristics. At first glance, insignificant differences in the courtship ritual and the exchange of visual, sound, and chemical stimuli will prevent the continuation of courtship.

An important isolating mechanism that makes it difficult to cross closely related species is the emergence of morphophysiological differences in the reproductive organs (morphophysiological isolation).

The second large group of isolating mechanisms in nature is associated with the occurrence of isolation after fertilization (intrinsic genetic isolation), including the death of zygotes after fertilization, the development of completely or partially sterile hybrids, as well as reduced viability of hybrids.

Lanskoy Grigory Nikolaevich domestic historiography of the economic history of Russia at the beginning of the 20th century Abstract of the dissertation

... fundamental ... XXcentury V general ... picture ... on the path to the modern period, domestic historiography of the economic history of Russia began XXcentury passed three ... XXcentury these views were distinguished by the greatest stability, only supplemented new ... World historian: XXcentury/ ...

Bagrova Natalya Viktorovna architectural-critical discourse as a phenomenon of national culture of the 20th century specialty 24 00 01 – theory and history of culture

Abstract of the dissertation

... on our sight, outlined new ... on dawn XXcentury, which continued in the social conditions of construction new ... on laws, trends, are common... Stand out three main groups... formulate fundamentallynew... 15 Revzin, G. I. Paintingpeace in architecture. Space and...

"a world without borders"

Document

Since the 70s XXcentury, first of all in... the brain in picture motor manifestations... communicated with disabled children. Emergence fundamentallynewviewson...see and perceive worldon personal level, ... conditionally divided onthree groups: ...

The concept of “hermaphroditism syndrome” refers to a group of disorders of sexual differentiation that accompany many congenital diseases and are manifested by quite diverse symptoms. Patients suffering from this pathology have characteristics of both men and women.

Below we will talk about why hermaphroditism occurs, what clinical manifestations it can be accompanied by, and also introduce the reader to the principles of diagnosis and treatment of this pathology.

False hermaphroditism is distinguished when the structure of the genitals does not correspond to the gender of the gonads (gonads). In this case, the genetic sex is determined by the affiliation of the gonads and is called pseudohermaphroditism, male or female, respectively. If a person has elements of both the testicle and ovary at the same time, this condition is called true hermaphroditism.

In the structure of urological and gynecological pathology, hermaphroditism is recorded in 2-6% of patients. There are no official statistics regarding this pathology today, but it is unofficially believed that hermaphroditism occurs more often than doctors register it. Such patients are often hidden under other diagnoses (“gonadal dysgenesis”, “adrenogenital syndrome” and others), and also receive therapy in psychiatric departments, since their sexual disorders are incorrectly assessed by doctors as diseases of the sexual centers of the brain.

Classification

Depending on the mechanism of development of hermaphroditism, there are 2 main forms of it: impaired differentiation of the genitals (genital organs) and impaired differentiation of the sex glands, or gonads.

There are 2 types of genital differentiation disorders:

Female hermaphroditism (partial appearance of male sexual characteristics, the set of chromosomes is 46 XX):
- congenital dysfunction of the adrenal cortex;
- intrauterine virilization of the fetus under the influence of external factors (if the mother suffers from any tumor that produces male sex hormones - androgens, or takes medications that have androgenic activity).
Male hermaphroditism (inadequate formation of male sexual characteristics; the karyotype looks like this: 46 XY):
- testicular feminization syndrome (tissues are sharply insensitive to androgens, which is why, despite the male genotype, and therefore the person’s belonging to this sex, he looks like a woman);
- deficiency of the enzyme 5-alpha reductase;
- insufficient testosterone synthesis.

Disorders of differentiation of the gonads are represented by the following forms of pathology:

bisexual gonad syndrome, or true hermaphroditism (the same person combines both male and female gonads);
Turner syndrome;
pure agenesis of the gonads (complete absence of the sex glands in the patient, the genitals are female, underdeveloped, secondary sexual characteristics are not determined);
dysgenesis (disorder of intrauterine development) of the testicles.

Causes of occurrence and mechanism of development of pathology

Both hereditary factors and factors affecting it from the outside can disrupt the normal development of the fetal genital organs.

The causes of disembryogenesis, as a rule, are:

mutations of genes in autosomes (non-sex chromosomes);
pathology in the area of sex chromosomes, both quantitative and qualitative;
external factors affecting the fetus’s body through its mother at a certain stage of development (the critical period in this situation is 8 weeks): tumors in the mother’s body that produce male sex hormones, her taking medications with androgenic activity, exposure to radioactive radiation, various types of intoxication .

Each of these factors can affect any of the stages of sex formation, as a result of which one or another set of disorders characteristic of hermaphroditism develops.

Symptoms

Let's look at each form of hermaphroditism in more detail.

Female pseudohermaphroditism

This pathology is associated with a defect in the enzyme 21- or 11-hydroxylase. It is inherited in an autosomal recessive manner (that is, it is not related to gender). The set of chromosomes in patients is female – 46 XX, the gonads are also female (ovaries), and are formed correctly. The external genitalia have characteristics of both male and female. The severity of these disorders depends on the severity of the mutation and varies from mild hypertrophy (increase in size) of the clitoris to the formation of external genitalia, almost similar to male ones.

The disease is also accompanied by severe disturbances in the level of electrolytes in the blood, which are associated with a deficiency of the hormone aldosterone. In addition, the patient may be diagnosed with diarrhea, which is caused by increased blood volume and high sodium levels in the blood, resulting from a deficiency of the 11-hydroxylase enzyme.

Male pseudohermaphroditism

As a rule, it manifests itself as androgen insensitivity syndrome. The pattern of inheritance is X-linked.

Testicular feminization syndrome may develop due to a mutation in the androgen receptor gene. It is accompanied by insensitivity of the tissues of the male body to male sex hormones (androgens) and, on the contrary, good sensitivity to female hormones (estrogens). This pathology is characterized by the following symptoms:

chromosome set 46 XY, but looks sick like a woman;
aplasia (absence) of the vagina;
insufficient hair growth for a man or complete absence of the latter;
development of mammary glands characteristic of women;
primary (although the genitals are developed according to the female type, they are absent);
absence of a uterus.

In patients with this pathology, the male sex glands (testicles) are formed correctly, but are located not in the scrotum (it is missing after all), but in the inguinal canals, the area of the labia majora, and in the abdominal cavity.

Depending on how insensitive the patient’s body tissues are to androgens, complete and incomplete forms of testicular feminization are distinguished. There is a variety of this pathology in which the patient’s external genitalia look almost normal, close in appearance to those of healthy men. This condition is called Reifenstein syndrome.

Also, false male hermaphroditism may be a manifestation of disorders of testosterone synthesis caused by a deficiency of certain enzymes.

Disorders of gonadal differentiation

Pure gonadal agenesis syndrome

This pathology occurs due to point mutations on the X or Y chromosome. Patients are of normal height, their secondary sexual characteristics are underdeveloped, there is sexual infantilism and primary amenorrhea (initially no menstruation).

The external genitalia, as a rule, have the appearance of a woman. In men, they sometimes develop according to the male pattern.

Turner syndrome

It is caused by a genetic mutation - monosomy (full or partial) on the X chromosome. There are also anomalies in the structure of this chromosome or mosaic variants of the mutation.

As a result of this anomaly, the processes of differentiation of the gonads and the function of the ovaries are disrupted. On both sides there is dysgenesis of the gonads, which are represented by striae.

Genes on non-sex chromosomes are also affected. The growth processes of somatic cells and their differentiation are disrupted. Such patients are always short and have many different other anomalies (for example, a short neck, pterygoid folds of the neck, high palate, heart defects, kidney defects, and others).

Testicular dysgenesis

There are 2 forms of it:

bilateral (two-sided) – the testicles are underdeveloped on both sides and do not produce normal sperm; karyotype – 46 XY, however, abnormalities in the structure of the X chromosome are detected; the internal genital organs are developed according to the female type, the external ones can have characteristics of both male and female; the testicles do not produce testosterone, so the level of sex hormones in the patient’s blood is sharply reduced;
mixed - the gonads are developed asymmetrically; on the one hand they are represented by a normal testicle with preserved reproductive function, on the other - by a testicle; in adolescence, some patients develop secondary sexual characteristics of the male type; When studying the chromosome set, as a rule, anomalies in the form of mosaicism are revealed.

True hermaphroditism

This pathology is also called bisexual gonad syndrome. This is a rare disease characterized by the presence of structural elements of both the testicle and ovary in the same person. They can be formed separately from each other, but in some cases, patients have so-called ovotestis - tissue of both sex glands in one organ.

The set of chromosomes in true hermaphroditism is usually normal female, but in some cases it is male. Sex chromosome mosaicism also occurs.

The symptoms of this pathology are quite varied and depend on the activity of the testicular or ovarian tissue. The external genitalia are represented by both female and male elements.

Diagnostic principles

Ultrasound allows you to assess the condition of the gonads.

The diagnosis process, as in other clinical situations, includes 4 stages:

collection of complaints, anamnesis (history) of life and current illness;
objective examination;
laboratory diagnostics;
instrumental diagnostics.

Let's look at each of them in more detail.

Complaints and anamnesis

Among other data, in case of suspected hermaphroditism, the following points are of particular importance:

whether the patient’s immediate family suffers from similar disorders;
the fact of removal surgery in childhood (this and the previous points will lead the doctor to think about testicular feminization syndrome);
characteristics and growth rates in childhood and adolescence (if the growth rate in the first years of a child’s life was ahead of that of peers, and at 9-10 years old it stopped or slowed down sharply, the doctor should think about the diagnosis of “dysfunction of the adrenal cortex”, which arose against the background of increased levels of androgens in blood; this pathology may also be suspected in a child with).

Objective examination

The most important point here is to assess the patient's sexual development and body type. In addition to sexual infantilism, the detection of growth disorders and minor anomalies in the development of other organs and systems allows us to make a diagnosis of “Turner syndrome” even before karyotyping.

If, upon palpation of a man’s testicles, they are detected in the inguinal canal or in the thickness of the labia majora, male pseudohermaphroditism can be suspected. The discovery of the absence of a uterus will further convince the doctor of this diagnosis.

Laboratory diagnostics

The most informative method for diagnosing this pathology is karyotyping - a cytogenetic study of chromosomes - their number and structure.

Also, in patients with suspected hermaphroditism, the concentration in the blood of luteinizing and follicle-stimulating hormones, testosterone and estradiol, and, less often, mineralo- and glucocorticoids is determined.

In difficult diagnostic situations, a hCG test is performed.

Instrumental diagnostic methods

To assess the condition of the genital organs, the patient is prescribed an ultrasound of the pelvic organs, and in some cases, computed tomography of this area.

The most informative is an endoscopic examination of the internal genital organs and their biopsy.

Principles of treatment

The main direction of treatment for hermaphroditism is surgical intervention to correct the patient’s gender. The latter chooses his gender, and in accordance with this decision, surgeons reconstruct the external genitalia.

Also, in many clinical situations, such patients are recommended to undergo a bilateral gonadectomy - completely remove the gonads (testes or ovaries).

Female patients, if they have hypogonadism, are prescribed hormonal therapy. It is also indicated for patients whose gonads have been removed. In the latter case, the purpose of taking hormones is to prevent the development of post-castration syndrome (sex hormone deficiency).

So, patients can be prescribed the following drugs:

estradiol (one of its trade names is Proginova, there are others);
COCs (combined oral contraceptives) - Mercilon, Logest, Novinet, Yarina, Zhanin and others;
drugs for hormone replacement therapy for disorders that arise after the onset (climodien, femoston, and so on);
synthetic analogues of glucocorticoids and mineralocorticoids (depending on which hormone deficiency occurs in a particular patient); they are prescribed for adrenal dysfunction, which results in sexual disorders;
to stimulate the growth of the patient, people suffering from Turner syndrome are prescribed somatotropic hormone preparations (Norditropin and others);
testosterone (omnadren, sustanon) – it is recommended to use it for the purpose of hormonal therapy for males.

Patients suffering from hermaphroditism, even after surgery, should be under the supervision of an endocrinologist. Also, many of them are advised to consult a psychotherapist, sexologist or psychologist.

Hermaphroditismor disorder of sexual differentiation is a whole group of developmental defects with various clinical manifestations and genetic diversity, characterized by the presence of characteristics of both sexes in one individual. The term "hermaphroditism" is associated with the ancient Greek myth, according to which the son of two Greek gods - Hermes and Aphrodite - Hermaphrodite was turned into a bisexual creature. Hermaphroditism is otherwise called bisexuality, bisexuality, and androgeny. Natural hermaphroditism occurs in nature in some plant species, in representatives of the coelenterate family, in flatworms, in a number of mollusks and fish.

Distinguish false hermaphroditism, or pseudohermaphroditism, which implies the presence of external genitalia of both sexes in one organism, and true, or gonadal, hermaphroditism, in which the individual's gonads are represented by both ovaries and testes. Identifying the form of sexual differentiation disorder allows you to choose the appropriate method for correcting the pathology. At the birth of a baby with bisexual external genitalia, karyotyping and ultrasound examination of the pelvic organs are performed to determine the gender of the gonads, which will allow the civil gender of the child to be established and documented.

True hermaphroditism is extremely rare. The prevalence of pseudohermaphroditism is approximately 1 case per two thousand newborns.

Classification of hermaphroditism

All manifestations of hermaphroditism can be divided into 2 groups - impaired differentiation of the external genitalia and impaired differentiation of the gonads.

Defects of genital differentiation include:

1. Female hermaphroditism, characterized by karyotype 46XX with partial virilization. Occurs with congenital dysfunction of the adrenal cortex or intrauterine virilization of the fetus associated with the presence of androgen-secreting tumors in a woman, or with the use of androgen-active drugs.

2. Male hermaphroditism, which is characterized by a 46XY karyotype and inadequate virilization. The occurrence of this form of hermaphroditism is facilitated by testicular feminization syndrome, deficiency of 5a-reductase and defects in testosterone synthesis.

Disturbances in gonadal differentiation may manifest as:
- true hermaphroditism;
- Turner syndrome;
- testicular dysgenesis;
- pure gonadal agenesis.

Causes and mechanism of development of hermaphroditism

The development of hermaphroditism is based on a violation of the normal embryonic development of the fetus due to hereditary or external causes. Hereditary causes can be associated with quantitative and qualitative chromosomal defects of sex chromosomes and autosomes - gene mutations, translocations, deletions. External causes that contribute to the development of hermaphroditism include intoxication, radiation, androgen-producing tumors in the body of a pregnant woman, and taking medications with androgenic activity. The impact of these factors is especially dangerous during critical periods of embryonic development of the fetus (in the seventh to eighth week of pregnancy).

The formation of an individual's gender occurs in several stages. It all starts with the determination of genetic sex and differentiation of the gonads during intrauterine development, based on which the potential direction of the reproductive function is outlined. After this, a hormonal background is formed with a predominance of male or female sex hormones. The process of a child’s sexual identity ends with the formation of somatic and civil gender, which determines the direction of sex education. Genetic determination of sex and the expected path of development of the gonads depend on genes, and the development of the gonads and genitals according to the male type is determined by factors that are produced by the fetal gonads. Based on this, hermaphroditism can occur due to a defect in one of the intrauterine stages of sex formation.

Signs of hermaphroditism

False female hermaphroditism characterized by a female karyotype 46XX and gonads characteristic of the female sex - ovaries. But the external genitalia have a bisexual structure. Patients experience varying degrees of virilization from a slight enlargement of the clitoris to the formation of genital organs similar in structure to those of men. The entrance to the vagina narrows. Since the disease is most often associated with enzymatic deficiency of 21-hydroxylase and 11-hydroxylase, which is accompanied by impaired potassium-sodium metabolism, patients complain of edema and increased blood pressure.

False male hermaphroditism, otherwise called androgen insensitivity syndrome or testicular feminization syndrome, which is characterized by a male karyotype 46XY against the background of a female phenotype characterized by spontaneous growth of the mammary glands, scanty male hair growth, absence of the uterus and vaginal aplasia. In this case, the testicles are located in the inguinal canals, labia majora or in the abdominal cavity. If the phenotype has external genitalia similar to normal male ones, then we speak of Reifenstein syndrome.

Occasionally, the cause of male hermaphroditism can be a congenital pathology of testosterone production in the adrenal glands and testes, which is manifested either by its insufficient secretion or by a disrupted mechanism of action.

Turner syndromeis one of the variants of impaired gonadal differentiation and is caused by the complete absence of the X chromosome or its structural abnormality. A defect in the X chromosome leads to deformations in the expression of genes that control the differentiation and function of the ovaries, which ultimately leads to disruption of the formation of gonads and the formation of gonads instead. The genes of autosomal chromosomes that control the growth and differentiation of cells of internal organs also undergo transformations, which leads to short stature and the development of a high palate. In addition, when examining patients, ear deformities and a short neck with skin folds on the back in the form of “wings” are revealed. During instrumental examination of patients, heart and kidney defects are detected.

In patients with pure gonadal dysgenesis syndrome The genitals are usually formed according to the female type; only with karyotype 46XY is virilization of the genitals sometimes observed. The growth of the patients is normal, external sexual characteristics are not expressed, and sexual infantilism is characteristic. In patients with mixed gonadal dysgenesis Asymmetric formation of the internal genital organs is noted. Thus, on one side they have a streak, and on the other, a testicle, the functionality of which is preserved.

With true hermaphroditism, which is extremely rare, the patient is found to have elements of ovarian and testicular tissue. Signs of this form of hermaphroditism are variable and depend on the activity of ovarian and testicular tissues. The genitals are arranged according to the bisexual type.

Methods for diagnosing hermaphroditism

Diagnosis of the disease consists of the collection and analysis of anamnestic data, examination, instrumental and laboratory research methods.

When collecting anamnesis, it is important to find out whether close relatives on the maternal side had similar disorders. It is necessary to focus on the nature and rate of growth during childhood and puberty, since active growth up to 10 years with its subsequent cessation may indicate adrenal dysfunction as a result of hyperandrogenemia. This process can also be suspected based on the early appearance of pubertal hair.

When examining the patient, the physique is assessed, which can inform about deviations that occur during puberty. For example, the physique of a “eunuch” is formed due to hypogonadism, the basis of which may be hermaphroditism. Short stature, combined with sexual infantilism, makes one think about Turner syndrome. False male hermaphroditism can be suspected by palpation of testicles in the labia majora or in the inguinal canals.

Laboratory tests for the diagnosis of hermaphroditism come down to determining chromosomal and gene mutations using karyotyping and gene research. Determining the level of gonadotropins and sex hormones in the blood makes it possible to differentiate hermaphroditism from other diseases. To identify the potential direction of sexual adaptation in patients with a mixed form of gonadal dysgenesis, a test with human chorionic gonadotropin is performed. And to diagnose patients with impaired synthesis of testosterone and androgens, the level of testosterone, glucocorticoid and mineralocorticoid hormones, as well as their precursors is examined, using a stimulation test with analogues of adrenocorticotropic hormone.

Using ultrasound and computed tomography, information about the condition of the internal genital organs is obtained.

Treatment of hermaphroditism

The main objectives of therapeutic measures for the correction of hermaphroditism are to determine the civil sex and the formation of all the signs necessary for this in the patient, and to ensure normal hormonal levels. Treatment of patients with hermaphroditism consists of surgical gender reassignment and hormone replacement therapy.

Surgical gender reassignment is aimed at the formation of the external genitalia using masculinizing or feminizing reconstruction and at determining the fate of the gonads. Currently, due to the high risk of tumor development, surgeons resort to bilateral removal of the gonads in all patients with a female phenotype, but with a male karyotype.

Hormonal therapy for patients with females is carried out to prevent the manifestations of post-castration syndrome, which develops in patients who have had their gonads removed. Hormonal treatment consists of using only estradiol drugs - estrofema, progynova. In addition, it is possible to prescribe combined oral contraceptives, such as Mercilon, Novinet, Zhanine, Diane-35. To correct postmenopausal disorders, monophasic and biphasic hormone replacement therapy drugs are used. Consultation with an endocrinologist

Specialists at the Northwestern Endocrinology Center diagnose and treat diseases of the endocrine system. The center's endocrinologists base their work on the recommendations of the European Association of Endocrinologists and the American Association of Clinical Endocrinologists. Modern diagnostic and treatment technologies ensure optimal treatment results.

Pelvic ultrasound

Pelvic ultrasound – ultrasound examination of the pelvic organs (uterus, fallopian tubes, vagina, ovaries, bladder). A pelvic ultrasound can be performed to diagnose diseases of the female genital organs or bladder, as well as to diagnose the condition of the fetus during pregnancy or diagnose pregnancy itself.

Consultation with a urologist-andrologist

Andrology is a field of medicine that studies men, male anatomy and physiology, diseases of the male genital area and methods of their treatment. At the moment, there is no specialization in andrology in Russia, so specialists who want to engage in this field of medicine must receive a basic education in urology followed by additional specialization in endocrinology

Consultation with a pediatric endocrinologist

Very often, patients under 18 years of age come to see specialists at the Northwestern Endocrinology Center. For them, the center has special doctors - pediatric endocrinologists.

Ultrasound of the scrotum and testicles

Ultrasound of the scrotum and testicles is one of the most effective ways to examine the male reproductive system, including the testicles, spermatic cords and appendages

Editor's Choice

Where do human viruses come from?

Exactly a century ago, in December 1918, world medicine received a resounding slap in the face, from which it could not recover for many decades....

Damocles rises highest above the plane of the ecliptic

A collection of interesting problems and questions A. At the pole, the Sun is above the horizon for half a year, and below the horizon for half a year. And the Moon? B. To...

Fake news about getting HIV from eating a banana and drinking Pepsi

Probably only the lazy have not heard the news about bananas and Pepsi with HIV infection. Social networks are periodically full of photos from...

What are the advantages and disadvantages of the phenomenon of hermaphroditism

Hermaphroditism (named after the Greek god Hermaphroditus, Greek Ερμαφρόδιτος) is the simultaneous or sequential presence of male...

Hermaphroditism: symptoms, types, causes, diagnostic methods

Hermaphroditism (named after the Greek god Hermaphroditus, Greek Ερμαφρόδιτος) is the simultaneous or sequential presence of male...

Loss of a portion of a chromosome is called

All hereditary diseases are caused by mutations—defects in the genetic material. Chromosomal diseases are diseases caused by...

Types of tissue and their structural features and location in the body Concept of tissue

Structure and biological role of tissues of the human body: General instructions: Tissue is a collection of cells that have similar...

Properties of nuclear forces What are nuclear forces called and what are their properties

Nuclear forces provide attraction - this follows from the very fact of the existence of stable nuclei consisting of protons and...

History of the development of antisepsis and asepsis Antisepsis and asepsis history of medicine

Abstract On the topic History of antisepsis and asepsis in Russia §1. Development of the idea of methods of treating wounds in the middle of the 11th century in Russia...

New

Popular

Hermaphroditism: symptoms, types, causes, diagnostic methods. The phenomenon of hermaphroditism. Natural and anatomical hermaphroditism. Intersexuality and. Gynandromorphism Complaints and anamnesis

Send your good work in the knowledge base is simple. Use the form below

2. Possible disorders of sexual differentiation

3. Classification

5. True hermaphroditism

6. Mixed gonadal dysgenesis

7. Male pseudohermaphroditism

8. Female pseudohermaphroditism

Similar documents

Bagrova Natalya Viktorovna architectural-critical discourse as a phenomenon of national culture of the 20th century specialty 24 00 01 – theory and history of culture

"a world without borders"

Classification

Causes of occurrence and mechanism of development of pathology

Symptoms

Female pseudohermaphroditism

Male pseudohermaphroditism

Disorders of gonadal differentiation

Pure gonadal agenesis syndrome

Turner syndrome

Testicular dysgenesis

True hermaphroditism

Diagnostic principles

Complaints and anamnesis

Objective examination

Laboratory diagnostics

Instrumental diagnostic methods

Principles of treatment

Classification of hermaphroditism

Causes and mechanism of development of hermaphroditism

Pelvic ultrasound

Consultation with a urologist-andrologist

Consultation with a pediatric endocrinologist

Ultrasound of the scrotum and testicles