The female body is special, it serves the birth of a new life. This leaves a special imprint on the structure and functions of the female body, so that the woman could safely conceive, carry, give birth and feed the child.
The body of a girl-future mother is not a female body in miniature, so it has a structure and functions different from the body of an adult.
Currently, in the development of girls allocate certain periods :
1) prenatal (before birth);
2) the period of newborns (from birth to 10-20 days after birth);
3) the period of infancy (1 month-1 year);
4) period of milk teeth :
(a) pre-school (2-4 years);
b) preschool (5-6 years);
5) adolescence (Junior school age-7-8 years);
6) prepubertal (from 8 years to menarche-the first menstrual period);
7) phase I of puberty (from menarche to 14 years);
8) II phase of puberty , or adolescence (15-17 years).
Gynecologists 3, 4 and 5-th periods are United under the name “neutral” (period of hormonal rest).
This division of childhood into separate periods is based on the characteristic for each period of age anatomical and physiological characteristics of the child’s body.
This period of development of the girl is usually calculated in 10 lunar months, or 40 weeks (1 lunar month corresponds to 4 weeks), or 280 days from the first day of the last menstrual cycle of the mother, or 270 days from the date of conception. In this period, there are several phases :
1) the phase of embryonic development (up to 3 months), when the formation of the fetus, laying and the beginning of the functioning of the main organs and systems of the body;
2) the phase of placental development, characterized by fetal growth and the active function of the placenta, which serves not only as an intermediate between the mother and the fetus (in which nutrients from the mother’s body go to the fetus), but also a self-functioning organ (including hormonal), which has a diverse effect on the fetus.
Physical development of the fetus in this period is its formation and intensive growth due to the nutrients coming from the maternal organism via the placenta.
The length of the body of the fetus is calculated by the formula: up to the 5th lunar month growth in centimeters is equal to the number of months of fetal development, squared, for example, in the 1st month – 1 cm, in the 2nd month-4 cm, in the 3rd month-9 cm, etc.
From the 6th lunar month, the growth of the fetus in centimeters is equal to the number of months of intrauterine development multiplied by 5, for example: in 6 months-30 cm, in 7 months-35 cm, in 8 months-40 cm, etc.
Modern ultrasound and biochemical studies have confirmed that the laying, formation and even the beginning (formation) of all organs and systems of the future woman occur in a fairly early period of pregnancy.
The girl is formed already from 5-8 weeks of pregnancy, and this occurs under the influence of the “female” set of chromosomes (karyotype 46, XX): at first, the sex cells scattered in the mesenchymal tissue are grouped into the cortical and cerebral area of the ovaries; the common for boys and girls sexual tubercle turns in girls into the clitoris, sexual folds-into small labia, sex rollers-into large labia; from the urogenital sinus are formed bartolinievy glands (large glands of the vestibule) and the lower 2/3 of the vagina (in General, the development of the kidneys, adrenal glands and gonads are closely interrelated, they have a common origin from the same area of the primary mesoderm of the embryo and develop almost parallel); the internal genitals of the girl (fallopian tubes, uterus and upper 1/3 of the vagina) are formed from the ducts of Muller.
This process is called primary sexual differentiation . The pituitary gland (the Central point of regulation of hormones in the body) appears in the embryo at the 5th week, and the hypothalamus (guiding the pituitary gland)-from the 8th week, and already from the 9th week of pregnancy, the pituitary gland under the influence of the hypothalamus secretesizes its hormones (they can be found in the blood of the embryo, and in the amniotic fluid surrounding it).
From the 3rd month of pregnancy, the mother’s placenta begins to function actively.
By the 17-20-th week of the intrauterine period, almost all the organs of the fetus are formed and gradually began to function. The development of the hypothalamus as the highest regulatory center ends later-by the 28th week of pregnancy.
From all the above we can conclude that for the proper formation and development of the girl is particularly crucial intrauterine period of development in the early stages (from the 5th to 8-9 weeks).
The behavior of mothers at this time is very important: all factors that can disrupt organogenesis (formation of organs), namely, alcohol, ionizing radiation, microwave radiation, certain chemicals, drugs, viruses, stress, can cause developmental abnormalities, up to very severe and incompatible with life. And what should especially alert a woman: in these terms (5-6 weeks), she may not know or think about pregnancy, so a woman who wants to get pregnant and give birth to a healthy child, should always think about what can cause a violation in the development of the fetus, and try to avoid these factors.
In addition, according to the latest ultrasound data, the fetus in the intrauterine period already behaves as a person and responds to the mental state of his mother and to the factors that are pleasant to him: to music, to this or that food, smells, different noises, touches to the mother’s stomach and the approach of the father, his voice, etc.
The General mood of the mother and the whole family for pregnancy also plays a role.
Therefore, for the proper formation of the physical and neuropsychological development of a girl, a pregnant woman must create the appropriate conditions: a good, calm atmosphere at home, the right sleep and rest, proper nutrition. Viral infections and medications should be avoided. It is also necessary to register in time in the women’s consultation under the supervision of a doctor (up to 12 weeks of pregnancy).
From the moment of separation of the fetus from the mother (i.e. from the moment of umbilical cord cutting) a new stage in the girl’s life begins, a very special period – the period of newborn . The first fetus was in a warm, dark, quiet and satiety, quiet “floating” in amniotic fluid. And suddenly it begins to the pain, compress the muscles of the uterus, somewhere abruptly pushing, and the fetus periodically lacks oxygen. The fruit is clustered, the maximum compressed in anticipation of the worst, his nerves are tense. The hardest thing – the last frontier – a breakthrough through the vulva (which before it is stretched strongly). And suddenly-very bright light, cold, strong suffocation (because the lungs have not yet opened, are not accustomed to the air). From all this suffering and fear of death, the fetus takes a sharp breath to scream; in the lungs immediately comes cold, dry, burning throat and all the inside air. The fetus screams more and more from the pain, the air comes more and more, all the alveoli open, and the child begins to breathe atmospheric air. This is a huge stress for a newborn.
The newborn period lasts 2-3 weeks (sometimes 10 days, rarely up to 1 month), and this is a very special period. There is a sharp reorganization of the girl’s body for life not in the mother’s body, but in severe environmental conditions for her, where it is too light, cold and hungry. Absolutely all of its organs are in a state of unstable equilibrium, they are rebuilt and begin to work actively. In the first seconds and minutes of life, extrauterine blood circulation is established, without the participation of the placenta, the blood pathways of the embryo are regressed; on the skin – an inflammatory process followed by exfoliation; drying and falling off of the umbilical cord, followed by healing of the umbilical wound; weight loss with its subsequent restoration; change in the composition and physical and chemical properties of blood; increase in basic metabolism; inclusion in the work of the kidneys, gastrointestinal tract.
In the nervous system of the newborn the processes of inhibition and excitation are not the same, dominated by a braking process. Perhaps it is a “protective” braking at the time of adaptation of the newborn to the environment.
Affect and imperfection of receptors, and the incompleteness of the formation of the Central and peripheral nervous systems. But the immunity in the newborn is relatively high due to passive transfer of antibodies the mother (through the placenta and through breast milk). Therefore, in this period, infectious diseases (measles, scarlet fever, diphtheria) are very rare, but the susceptibility of newborns to pyogenic staphylococci, streptococci, as well as pathogenic strains of E. coli remains.
In hormonal terms, a newborn girl (and a boy too) is experiencing a so-called sexual crisis of newborns . The fact is that during pregnancy, from the 3rd month, the girl is almost completely under the influence of the mother’s actively functioning placenta, which secretes a large number of female sex hormones. After birth, communication with the mother and her hormones stops, their level in the girl’s blood immediately drops, and this stimulates the production in the girl’s pituitary gland of FSH (follicle stimulating hormone) and LH (luteinizing hormone), which briefly, but strongly enough force the ovaries of the newborn to produce estrogens in them – female sex hormones. Also in the pituitary gland, the production of prolactin, which controls the mammary glands, is stimulated.
As a result, the newborn girl is breast engorging and even the release of colostrum from the nipples, as well as other manifestations of increased levels of female sex hormones (estrogens) – hyperestrogenia: swelling of the external genitals (vulva) and clitoris, increased mucous discharge from the vagina (the entrance to the vagina can be closed by viscous mucus), mucus loosened, in the contents of the vagina there are sticks of lactic fermentation, the reaction of the contents – acidic. In some cases, there are bloody, menstrual-like discharge. The girl’s uterus is in the abdominal cavity, not in the pelvis, but above the entrance to the pelvis. Length of the uterus – 3 cm, its weight is 4 g, the ratio of the length of the cervix and body of the uterus is about 3 to 1, i.e. the neck is longer than the uterus itself 3 times (in adults Vice versa). In the mucous membrane of the uterus (endometrium), there is a strong proliferation (proliferation) and even secretory changes (mucosa begins to secrete a secret). And when these secretory changes reach their apogee (in some isolated cases in newborn girls), there is a rejection of the functional layer of the endometrium, and this is menstruation. In place of the external OS of the cervix is often pseudo. Fallopian tubes are relatively long (about 35 mm), strongly twisted (since they are attached to the wide ligaments of the uterus, and these ligaments are still short, underdeveloped), but the tubes are passable throughout. The ovaries are located in the abdominal cavity, while they have a cylindrical or prismatic elongated shape, their length is 1.5 – 2 cm, width–0.5 cm, thickness – 0.1 – 0.35 cm, the surface is smooth.
In the ovaries-primordial (ie, primary, novice development) follicles, there are about 700 000, many atrophic follicles, but there are also Mature.
After a hormonal crisis, the girl more or less gets used to the new conditions of her existence (she lives at the expense of unconditional, innate reflexes, the most important of them – food, then – protective and defensive), and the newborn enters a new phase of its development-the period of infancy, and from a hormonal point of view from 1 month to 8 years – a neutral period when the level of sex hormones is at a minimum level.
Physical development of the girl in different age periods and laws of increase of length and body weight
The greatest intensity of growth is observed in infancy, especially during the first and second quarters of the first year of life of the girl.