Mammary gland morphogenesis (mammogenesis) begins in the embryonic phase of mammalian development and ends during pregnancy.
Antenatal mammogenesis. The mammary glands in animals are laid from ectodermal rudiments at an early stage (in cattle - at the second month) of embryonic development.
By the time of birth, most mammals have formed nipples, ligaments, and interlobular septa. The ducts are still in their infancy, and instead of the parenchyma there is adipose tissue.
Postnatal mammogenesis before puberty manifested by the slow growth of adipose and loose connective tissues.
The most intensive development of the gland occurs before the first estrus and is accompanied by the formation of delicate, well-vascularized tissue around the ducts.
With the onset of regular sexual cycles, mainly the ductal and milk-collecting systems of the glands are actively developing, and the alveoli and lobules, in the absence of fertilization, gradually increase the intensity of growth with each new estrus.
By the age of 10-12 months in cattle, the udder consists mainly of adipose tissue enclosed in the stroma, a system of ducts and islands of glandular parenchyma near the ducts and the cistern of the gland.
The glandular tissue actively develops during pregnancy. In the first half of pregnancy, the development of the duct system is completed and a tubular gland is formed. After that (from the 5th to the 7th month of pregnancy in cattle), a lobular-alveolar structure of the glandular parenchyma is formed, and then (in cattle by 6-8 months) myoepithelial cells are formed, which, 2-3 months before birth, begin to produce a secret with fat globules and parenchyma cells. In the last month of pregnancy, colostrum is formed, and milk is produced in the post-colostrum period.
In the early stages of the embryonic period, mammogenesis is regulated by mesenchymal factors, and at later stages by sex steroids (for example, fetal androgens inhibit this process, and a male type of gland development is formed).
In postnatal ontogenesis, the growth of the mammary glands in females is controlled by the hormones of the ovaries (the development of glandular tissue during pregnancy occurs with the dominance of the corpus luteum and hormones of the placenta), adenohypophysis, and adrenal glands.
In addition to estrogen and progesterone, hormones necessary for the growth and development of mammary gland tissue in mature non-pregnant females also include insulin, cortisol, and prolactin. These hormones regulate the proliferation and differentiation of epithelial cells (ducts and alveoli), as well as the formation of the lobular-alveolar structure of the gland with the capillary system.
Estrogens, progesterone and insulin cause growth mainly of the ducts and partly of the alveoli of the mammary gland. The development of alveolar myoepithelium is controlled by estrogens, and progesterone inhibits the contractile activity of a mature myoepithelial cell during the lactation period (slows down the onset of the reaction of milk secretion from the alveoli to oxytocin and acetylcholine). Corticosteroids and prolactin (sometimes growth hormone) accelerate the formation of subcellular structures that synthesize milk components.
The nervous system also plays an important role in mammogenesis. Denervation of the glands in immature animals leads to a lag in their further development.
The role of the nervous system in mammogenesis is also evidenced by the positive effect of udder massage in heifers and heifers on the development of glandular tissue and subsequent milk production of animals.
STRUCTURE OF THE BREAST
The number, shape and size of the mammary glands in animals have pronounced interspecies differences. Cows, goats, sheep, camels and mares that give birth to one or two cubs develop 1-2 pairs of glands. Multiparous animals have up to 8 pairs of glands.
The number of nipples in all animals (except mares) corresponds to the number of glands. Only in mares, the ducts from the two glands on each side open into one duct.
The four mammary glands of a cow form one covered with skin udder. It distinguishes between the base, the body and two (rarely three) pairs of nipples. On the back surface of the udder, the skin forms a milky mirror.
The udder is supported by skin, fascia and a longitudinal septum (divides the udder into halves). It consists of connective tissue stroma, adipose tissue, glandular parenchyma and capacitive system. Each half of the udder consists of anterior and posterior quarters with independent duct systems and a separate teat. The hindquarters are usually better developed than the forequarters. The hind quarters of the udder secrete approximately 30% each, and the anterior quarters 20% of the total milk.
The stroma of the mammary gland performs mechanical (due to the stroma, the udder stretches mainly in the horizontal direction) and protective functions. It also contains blood vessels and nerves.
The surface of the mammary gland is covered with thin, elastic, and the nipples with thick skin. On the nipples, the skin has no hair and is most richly innervated in the region of the canals and sphincter. In goats, sheep, mares, the skin contains sweat and sebaceous glands, while cows do not have these glands.
Udder adipose tissue in cows averages 43% of the organ mass. It contains many blood vessels and sympathetic nerves.
blood supply the udder is carried out on each side by the external pudendal and perineal arteries. The external pudendal artery, leaving the inguinal canal, divides into two dairy (exchange) arteries supplying blood to the skin and parenchyma of the corresponding half of the udder. The nipple is supplied with blood from the nipple artery. The arteries of the right and left halves of the udder form anastomoses with each other through the median supporting ligament, and the external pudendal and perineal arteries of one side are connected in the posterior quarter of the udder.
The main vessels that carry blood from the mammary gland are the external pudendal and saphenous abdominal veins. The deep branches of the veins have valves and run parallel to the corresponding arteries. The venous system of the udder is more complicated than the arterial system in terms of the number of anastomoses.
When standing, blood moves mainly through the saphenous abdominal veins, and when lying down, through the external pudendal vein. The opening through which the saphenous abdominal vein enters the chest cavity (on the side of the xiphoid process of the sternum) is called milk well. Its value is close to the size of the abdominal vein and reflects the level of development of the udder vascular system. The venous system of both halves of the udder is connected by anastomoses (especially at the base of the rear quarters of the udder). There are also many anastomoses between arterioles and venules.
The intensity of secretion in the mammary gland is closely related to its blood supply: volumetric blood flow increases significantly with the development of lactation and an increase in milk production, and hypogalactia is often associated with hemodynamic deviations.
lymphatic system The udder is represented by deep and superficial lymphatic vessels. Deep vessels begin in the glandular elements, and superficial ones - in the wall of the nipple and the skin of the udder. The main nodes located along these vessels are the cisternal and supraventral lymph nodes. From them, the lymph is sent to the deep inguinal lymph node.
In animals whose mammary gland is located only in the inguinal region, gland innervation provided by the lumbosacral plexus, and in animals with multiple glands - intercostal and lumbar nerves.
These nerves contain fibers of somatic (sensory) and autonomic (efferent) nerves.
Autonomic neurons approach ducts, blood vessels (regulate smooth muscle tone) and adipose tissue cells (regulate fat accumulation and extraction).
The most sensitive nerve endings are in the walls of the nipples (especially at the sphincter and nipple canal). The information from the tactile and temperature receptors of the mammary glands passing through these nerves provides a reflex regulation of lactation.
Udder parenchyma it is represented by glandular tissue and has a vine-like structure (Fig. 2). It consists of alveoli, ducts, channels, passages and cisterns that communicate with the nipple. Neighboring milk alveoli are combined into lobules, and lobules into lobes. Each milk alveolus at the blind end has the shape of a bubble (0.1 to 0.8 mm in diameter). The inner wall of the alveolus consists of secretory, and the outer wall of myoepithelial cells capable of contracting. Between the layers of these cells is a basement membrane with blood and lymphatic vessels.
Each alveolus passes into the primary milk ducts, which first form the ducts of the lobules, and then the lobes.
In cows, goats and sheep, the lobe ducts immediately open into the milk cisterns, while in cattle, the lobes of the lobes are first combined into the milk ducts and only after that they open into the mammary gland cisterna. The mouths of the ducts have sphincters. Milk from the alveoli and the ductal system enters the milk cistern, which is divided by a circular sphincter-like fold into the cisternal gland and the cistern of the nipple.
Each bovine mammary tank holds 2 liters or more, and the teat tank holds up to 50 ml. The cistern of the nipple passes into the nipple canal, the lumen of which is regulated by the sphincter. The cistern is most pronounced in cows and goats.
Shortly after fertilization, milk yields usually decrease, and a sharp drop in lactation in a cow is observed at 6 months of pregnancy.
Front dry period alveolar tissue is replaced by fatty tissue, the gland decreases and ceases to produce milk.
The optimal duration of the dry period in cattle is 45-60 days. Involution of the gland begins after launch cows (cessation of excretion of milk from the udder) and ends within 12-15 days. Highly productive cows are started gradually, by periodically skipping milking or incomplete milking of the udder.
The epithelium of the glandular tissue of lactating cows is well developed, the milk alveoli are large and filled with milk. With a long dry period, the cells of the glandular tissue become low, the alveoli collapse and contain accumulations of leukocytes, and the content of adipose tissue increases between the glandular lobules.
During the usual dry period, the alveoli are filled with a liquid or semi-liquid mass with accumulations of leukocytes.
After the completion of involution, regeneration of the secretory epithelium begins, new alveoli are formed, the amount of connective tissue decreases and the udder increases. This process is completed only after the colostrum period. Therefore, milk yields increase in the first months of lactation (in cattle from the 30th to the 70th-90th days after calving).
Animals with stable hormonal systems and developed udders can sometimes produce milk continuously for several years (“marathon milking”). However, this is rarely used in practice, as it leads to the annual loss of a calf, an irreversible gradual decrease in productivity, and animal disturbance during estrus.
For citation: Uvarova E.V. Premature development of the mammary glands in girls. Issues of pathogenesis, diagnosis and treatment // RMJ. Mother and child. 2008. No. 19. S. 1274
Premature thelarche (PT) in girls refers to unilateral or bilateral breast enlargement at an age that is 2.5 or more standard deviations (2.5SD or s) below the mean age of onset in a population of healthy children. Currently, in most countries of the world, puberty is regarded as premature in the presence of any of its signs in girls of the white race up to 7 years and the Negroid race up to 6 years of age. PT is one of the variants of gonadoliberin-independent isosexual precocious puberty (PPS), therefore it is often called peripheral or false. Premature thelarche occurs in 1% of girls under the age of 3 years and is 2-3 times higher than the frequency of true forms of PPS. Selective breast enlargement is most common in girls under the age of 3 and older than 6 years.
The mammary glands are target organs for the action of various peptide and steroid hormones, therefore they are sensitive to any violation of hormonal relationships by changing volume and structure.
It is assumed that the sensitivity of the mammary glands to hormonal influences appears in all mammals with birth, despite the fact that estrogen receptors in individuals of both sexes appear in the epithelium of the mammary gland tissue starting from the third trimester of pregnancy, and progesterone receptors - from 2-3 months after birth.
From the moment of birth, the mammary gland is a matrix consisting of fragments of the glandular-duct complex, immersed in the rudiment of the stromal-fat complex. At birth, the ductal system merges into a common sinus, which opens on the skin with a funnel-shaped depression. The proliferation of mesenchymal cells surrounding the sinus leads to the formation of an inverted nipple, and skin epithelial cells to the areola. Studies of autopsy material of mammary gland tissue of newborns have shown a great variety in the degree of development of the ductal system, ranging from simple blindly ending structures to well-developed branches with acini. The marked variants of the structure correspond to the peculiarities of the receptor interaction of the epithelial cells of the ducts with estrogens and epidermal growth factor, and the alveolar epithelium of the lobules with prolactin and progesterone of the mother's body. In mammary glands with acini and branching ducts, a specialized intra- and interlobular stroma develops.
In 80-90% of newborn girls and a number of boys, the mammary glands increase in size up to Ma2-3 by the 3-10th day of life, and colostrum begins to separate from the nipples due to rapid neonatal secretion of pituitary hormones during the period of sexual crisis (PRL, TSH, GR , ACTH) regardless of the structural features of the development of the ductal-alveolar complex.
As the level of pituitary hormones returns to the values of their tonic (basal) secretion, the mammary glands in newborns gradually decrease in size to Ma1 according to Tanner. On palpation, the body of the mammary gland does not exceed 1 cm in diameter and is completely hidden under a non-convex, and sometimes retracted areola. On the echograms, the mammary glands in newborns are represented by formations of an oblong form of medium echogenicity without differentiation of individual structural elements, the average size of which is 15 mm in length, 6 mm in the anterior-posterior direction and 14 mm in width. At the same time, superficial and deep sheets of the superficial fascia are clearly visible, which, as it were, "cover" the mammary gland.
In most cases, spontaneous reduction of the mammary glands to their original size occurs within 2-3 weeks. In 1.5-2% of infants, the increase in the mammary glands persists up to 3-6, and in some cases up to 8-10 months of life. In children aged 1-2 years, only short small-caliber ductal structures, braided with a dense stroma of fibroblasts, remain in the mammary glands. A similar structure of the mammary glands is preserved in children of both sexes until puberty. The resumption of growth and development of the mammary glands in girls occurs at the age of 8-9 years, therefore, up to 8 years, the breast tissue behind the nipple is not palpable, there is no discharge from the nipples.
With premature thelarche, an increase in the volume of the mammary glands is noted, as a rule, not exceeding 2 stages of development (Ma2) according to Tanner. The development of the mammary glands in girls with PT is characterized by a more rapid increase in the volume of the left breast.
The mammary gland at this stage of development is represented mainly by cells of adipose tissue, penetrated by a thin network of stromal elements and a large number of microvessels and neurons surrounding them. That is why the increased vascularization and edema that accompanies the proliferation of the ducts, stromal and fatty complex causes girls to feel fullness and pain (mastalgia or mastodynia) in the mammary glands. With PT, girls, as a rule, do not develop nipples, genital hair growth and signs of estrogenization of the external and internal genital organs do not appear.
PT in girls under 8 years of age can occur against the background of persistent follicular cysts, granulosa cell tumors of the ovaries, congenital and / or untreated hypothyroidism (Van Wyck-Grombach syndrome), germ cell tumors that produce estrogens, hCG and gonadotropins, as well as with exogenous administration of estrogens and estrogen-like compounds in the form of dosage forms or with food. PT occurs in McCune-Albright-Braitzev syndrome (MOB), when precocious puberty is caused by uncontrolled activation of estrogen synthesis as a result of a congenital mutation of the receptor protein (GSa-protein) gene.
In the anamnesis of girls with PT, as a rule, there are no data on gross pathology of the antenatal and postnatal periods of life. Physical development corresponds to age. The advancing of maturation of the skeletal system does not exceed 1.5-2 years and does not progress further. In some cases, girls with PT have episodic bursts of FSH and estradiol secretion against the background of pre-pubertal LH levels. Instability of gonadotropic regulation can lead to the progression of sexual development in 10% of patients. In girls with isolated PT, in 60-70% of cases, follicles are found in the ovaries, sometimes reaching sizes of 0.5-1.5 cm in diameter. In the hormonal status of children, deviations from the normative indicators of LH and FSH for age are most often absent. On the test with GnRH, girls with premature thelarche are characterized by an increase in the level of FSH response compared to healthy peers. The LH response is pre-pubertal in nature. Premature thelarche is not accompanied by an acceleration of physical development, bone age, as a rule, corresponds to the passport age.
In girls with PT, spontaneous regression of the mammary glands is possible within 1 year from the moment of their increase and further sexual development in accordance with age standards. According to Yu.A. Gur-ki-na, out of 106 girls with isolated PT during further follow-up, 71 had a transition to normal puberty, 22 had fibrocystic disease, 11 had a complete form of precocious puberty and 2 girls have delayed puberty.
Current international guidelines lack evidence to support medical treatment for idiopathic premature thelarch. Annual observation and temporary abstinence from vaccinations in girls with premature thelarche are proposed, given the possibility of breast enlargement after their implementation.
However, in many girls, an increase in volume is accompanied by pain in the mammary glands, causing sleep disturbance, increased excitability and the development of psychopathic reactions.
Today, in medicine, the trend is increasingly visible, which consists in the desire to develop new, more natural medicines that have no less effectiveness, combined with much greater safety of their use. In adolescent girls and in women of the reproductive period with mastalgia, herbal remedies containing components of extracts of sacred Vitex (Vitex agnus castus) are widely used. According to pharmacological and medical research, the fruits of Vitex Sacred have a unique ability to interact with D2-dopamine receptors. The dopaminergic effect of components having the chemical structure of diterpenes consists in dose-dependent inhibition of cAMP formation by lactotrophs of the anterior pituitary gland and, due to this, in inhibition of prolactin synthesis. Prolactin, together with estrogens and progesterone, controls the entire process of mammogenesis and the formation of intraorgan structures. In addition, the phytopreparation based on Vitex agnus castus normalizes the ratio of gonadotropic hormones, primarily reduces the secretion of FSH. Due to the complex effect on the hypothalamic-pituitary system, Vitex agnus castus helps to eliminate hormonal imbalance, narrow the ducts, reduce the activity of proliferative processes, and reduce the formation of the connective tissue component.
Currently in Russia there are a number of phytopreparations containing Vitex agnus castus. Among them, a well-deserved place is occupied by Cyclodinone O and Mastodinone O (Bionorica AG). The pharmaceutical company "Bionorica AG" is a leader in the field of research and production of herbal preparations based on sacred Vitex in Germany. Cyclodinone O is a monopreparation containing only Vitex agnus castus, Mastodinon O is a complex herbal preparation, which, in addition to sacred vitex, includes homeopathic dilutions of extracts of alpine violet, multi-colored iris, cornflower stalk, tiger lily, and also chilibuha ignatia.
Mastodinone O and Cyclodinone O are a successful achievement of modern phytoengineering - phytoneering, which combines the principles of phytotherapy with modern scientific developments. That is why herbal remedies are as effective as synthetic ones, but have no side effects. Both of these herbal remedies significantly reduce blood supply and, consequently, swelling of the mammary glands, help reduce pain, reverse the development of degenerative changes in mammary gland tissues. When taking drugs, patients note an improvement in well-being, emotional state and the disappearance of discomfort.
The problem of mastalgia in girls with PT is no less relevant, however, therapeutic measures are not provided.
At the request and with the informed consent of the parents, in 20 little girls, to eliminate discomfort in PT, the phytopreparation Cyclodinone O was used, which contains the fruits of the sacred vitex, otherwise called the common rod (Agni casti fructus), in drops for oral use. 100 grams of the solution contains 0.192-0.288 g of dry extract of the fruits of agnus castus, corresponding to 2.4 g of medicinal plant materials.
When examining girls, a detailed analysis of anamnestic data was used, a hormonal examination was performed with the determination of the level of LH, FSH, PRL, TSH, free thyroxine, estradiol, progesterone, testosterone, 17-OP, DHEA-S, including under conditions of stimulating hormonal tests, ultrasound pelvic organs, thyroid and mammary glands, according to the indications of ultrasound of the internal organs, MRI of the brain with contrast. All girls underwent EEG and determined bone age.
The inclusion criteria for the study were the age of the girl under 8 years of age, the absence of endocrine (diabetes mellitus, thyroid disease, VDH) and sub- and decompensated extragenital pathology. Exclusion criteria - age 8 years and older, refusal to take the drug, the presence of adverse reactions, malformations, cysts and tumors of the mammary gland.
The age of the girls ranged from 2.5 to 6 years. Clinical and anamnestic data indicated the absence of hereditary burden, pathology of the genital and endocrine organs, as the causes of PT. At the same time, a comprehensive examination of the CNS (EEG, REG and MRI of the brain) revealed changes in the CNS of a functional nature in the majority of patients (92%). Psycho-neurological abnormalities in the form of increased nervous excitability, hypertonicity and neurocirculatory dystonia were found in 12 girls. Organic diseases and brain tumors were not identified.
Anthropometric data, echography of the uterus, ovaries and thyroid gland testified to the correspondence of their size and structure to age. The biological age according to radiography of the hands (bone age) in all examined girls corresponded to the calendar age.
Visually, the mammary glands were developed without pronounced asymmetry and were a cone without elevation of the nipple and its pigmentation (stage Ma2 according to Tanner), there was no discharge from the nipples. Palpa-torno marked engorgement of both mammary glands. The denser tissue was determined directly behind the areola in the form of a truncated cone.
Echography of the mammary glands revealed formations of an oblong form of medium echogenicity without differentiation of individual structural elements. The thickness of breast tissue ranged from 3-4 to 5-7 mm.
Hormonal examination revealed the excess of the age level of FSH and PRL with the standard level of other peptide and steroid hormones. The PRL level ranged from 477.8 to 728 mIU/l. The concentration of estradiol and testosterone were below the reference indicators of age standards.
The data obtained made it possible to justify the appointment of Cyclodinone to the examined girls with PT. We have selected the following dosage of the drug: children under 3 years old took 5 drops per 15 ml of water, children under 7 years old - 10 drops per day for 3 months.
At the visit at the end of the 3rd month of treatment, 15 girls showed a decrease in the mammary glands to the age-appropriate degree (Ma1 according to Tanner) and the absence of pain in all 20 girls. In 5 girls, the size of the mammary glands decreased, but no complete regression was observed. As it turned out, these girls suffered acute respiratory viral infections with hyperthermia for 4-5 days during treatment.
Hormonal examination testified to the normalization of gonadotropic stimulation while maintaining the rest of the hormonal parameters at their original values.
Genital ultrasound data showed no deviations in the size of the uterus and ovaries from age standards. The mammary glands on the echograms were determined by a weakly expressed layer of tissue behind the areola, the structure corresponding to the stromal-fat component. In 15 girls with regressed mammary glands, the thickness of the stromal-glandular layer was 1.5-3 mm, in the remaining 5 young patients it was 4-5 mm. There were no signs of pathological formations in the mammary glands, which made it possible to continue taking Cyclodinone for another 3 months at the same dose with a positive effect.
Against the background of the use of Cyclodinone, taste discomfort, undesirable and adverse reactions from taking an alcohol-containing solution of Cyclodinone were not noted in any case.
Thus, the use of Cyclodinone in drops in girls with premature thelarche indicates good tolerance, no adverse reactions, and a pronounced therapeutic effect of sacred Vitex fruits to eliminate premature growth and soreness of the mammary glands.
Literature
1. Gurkin Yu.A. A modern view on the treatment of girls and girls suffering from pathology of the mammary glands Scientific and practical journal Medical Department.- 3(7).-vol. 03, pp. 90-97.
2. Dedov I.I., Semicheva T.V., Peterkova V.A. Sexual development of children: norm and pathology. - M., "Color It Studio" -2002, S. 1-232.
3. Zabolotskaya N.V., Zabolotsky V.S. Ultrasound mammography (training atlas). - M.: 2005.
4. Ilyin A.B., Beskrovny S.V. The mammary gland is an organ of the female reproductive system // Journal of Obstetrics and Women's Diseases.-2000.-vol. XLIX, issue 2 -C.51-53.
5. Yen S.S.K., Jaffe R.B. Internal genital organs: the action of steroid hormones on target organs. Reproductive endocrinology. Volume 2: translation from English. M.: Medicine. - 1998. -S. 298-301.
6. Clinical recommendations. Obstetrics and gynecology. Issue 2, ed. V.I. Kulakov. M.: 2008.- 560 S.
7. Levenets S.O., Verkhoshanova O.G., Perevozchikov V.V. Riven prolactin and yoga correction in girls with pre-existing thelarche// Women's Health.- 2007.-1 (29).-C 134-139.
8. Ozerova O.E. Normal echographic features of the structure of the mammary glands in different age periods, during pregnancy and lactation. SonoAce-International.- N9.- 2001.-p.50-57.
9. Ozerova O.E. Features of age echographic anatomy of the mammary gland (clinical lecture) // Problems of reproduction No. 5 -2005 P.86-91.
10. Standard principles for the examination and treatment of children and adolescents with gynecological diseases and disorders of sexual development. Edited by Uvarova E.V. "Triad-X", M. 2004., P.135.
11 Bareille P, Azcona C, Stanhope R: Multiple neonatal endocrinopathies in MCCune-Albright syndrome/ J Pediatr Child Health 1999;35: 315-318.
12. Beatrice A. Howard and Barry A. Custerson. Human breast development.//J. of Mammary Gland Biology and Neoplasia.-2000.-Vol.5, No. 2P.119-137. 118
13. Cardiff R.D. and Wellings S.R. The comparative pathology of human and mouse mammary glands.// J. Mammary Gland Biol. Neoplasia.-1999.-Vol. 4-P.105-122. 123.
14. Gruber C. J., Walter Tschugguel M.D., Schneeberger C., Ph.D., and Johannes C. Huber, M.D., Ph.D. Production and Action of Estrogens.//New England Journal of Medicine.-2002. Vol 346 No. 5-R.340-352. 145
15. Hiba J., Pozo E.D., Genazzani A., Pustella E., Lancranjan I., Sidiropoulus D., and Gunti J. Hormonal mechanism of milk secretion in the newborn.//J. Clin. Endocrinol. Metab.-1977.-Vol.44-P.973-976. 147
16. Kaplowitz PB, Oberfield SE: Reexamination of the age limit for defining when puberty is precocious in girls in the United States: implications for evaluation and treatment. Drug and Therapeutics and Executive Committees of the Lawson Wilkins Pediatric Endocrine Society. Pediatrics 1999, 104(4 Pt 1): 936-41
16. Kelly P.A., Bachelot A., Kedzia C., Hennighausen L., Ormandy C.J., Kopchick J.J., and Binart N. The role of prolactin and growth hormone in mammary gland development.// Mol. cell. Endocrinol.-2002.-Vol.197-P.127-131.
17. Laurence D.J., Monaghan P., and Gusterson B.A. The development of the normal human breast. //Oxf. Reu.Reprod.Biol.-1991.-Vol.13-P.149-174. instead of 200
18. Low LC, Wang Q: Gonadotropin independent precocious puberty. J Pediatr Endocrinol Metab 1998 Jul-Aug; 11(4): 497-507
19. Mastorakos G, Mitsiades NS, Doufas AG, Koutras DA: Hyperthyroidism in McCune-Albright syndrome with a review of thyroid abnormalities sixty years after the first report. Thyroid 1997 Jun; 7(3): 433-9.
20. Pediatric Endocrinology and Growth J.K.H. Wales et all.-2nd edition, 2003, p.41-85
21. Quigley CA, Pescovitz OH: Premature thelarche and precocious puberty. Curr Ther Endocrinol Metab 1997; 6:7-13
22. Quigley CA, Pescovitz OH: Premature thelarche and precocious puberty. Curr Ther Endocrinol Metab 1997; 6:7-13
23. R. Stanhope, C. Traggiai. Precocious Puberty (Complete, Partial). Sultan C(ed): Pediatric and Adolescent Gynecology. Evidence Based Clinical Practice. Endocr Dev. Basel, Karger, 2004, Vol.7. pp 57-65.
24. Russo J. and Russo I.H. Development of the human mammary gland. In Neville M.C. Daniel C.W. (ebs.) //The mammary gland: Development Regulation and Function, Plenum Press, New York.-1987.-P.67-93184
25. Shankar RR, Pescovitz OH. Precocious puberty. Adv Endocrinol Metab 1995;6:55-89.
26. Williams Textbook of Endocrinology P. Reed Larsen et all.- 10th edition, 2002, p.1170-1187.
In most full-term babies in the first days of life - due to the cessation of the influx of maternal sex hormones into the bloodstream - the so-called sexual crisis develops. On the 3-4th day after birth, engorgement or swelling of the mammary glands occurs in children, which may increase over the next 5-7 days. There may be redness of the mammary gland in a child, and a small amount of milk-like discharge may appear from the nipples. Physicians also call this phenomenon physiological mastopathy of newborns.
As noted by pediatric neonatologists, there may be a thickening of the mammary glands in children - right under the nipple. Education is always single, up to 2-3 cm in size. It may disappear in a couple of weeks, or it may not disappear for several months while the child is breastfed: some babies are more sensitive to the hormone prolactin, which contains breast milk.
Parents need to know that this is not a disease, but a specific reaction of the child's body. It is necessary to consult a doctor, but nothing needs to be treated, you should only carefully observe hygiene. Because its non-compliance is fraught with mastitis (inflammation of the breast) of newborns, which can turn into an abscess.
And in this case, the causes of diseases of the mammary glands in a child during infancy are infection, most often with staphylococci or streptococci, and the development of an inflammatory process that needs to be treated (see below).
An increase in the mammary glands in a child before the onset of puberty, in particular, in girls under 8 years old, is a deviation. According to doctors, this is premature thelarche, that is, the beginning of the development of the mammary glands before the entry of girls into puberty (which begins after 10 years). Premature thelarche is considered a benign isolated condition, so to speak, a local process, which consists in the development of the mammary glands without the appearance of other secondary sexual characteristics.
It can be caused by problems with the ovaries (cysts), adrenal glands, or thyroid gland (hypothyroidism), or the use of exogenous hormones or medications. So, a few years ago, Turkish researchers (Gazi University, Ankara) found that long-term use of fennel, used to regulate bowel movements in infants and relieve bloating, causes an increase in the mammary glands in a child and can lead to too early breast development in girls up to two years old. The fact is that the biologically active substances of this plant stimulate the synthesis of estrogens.
It should also be taken into account that the asymmetric development of the mammary glands in girls under the age of 12 corresponds to the peculiarities of this process: one gland (usually the left) develops earlier than the second, but, ultimately, the breasts become symmetrical.
According to some reports, about 4% of girls with premature thelarche have central precocious puberty. What does this mean? This is when an increase in the mammary glands in girls begins earlier than 8 years of age and is accompanied by hair growth of the pubic and axillary regions. To date, there are good reasons to consider one of the key causes of this pathology of mutations in the genes of leptin (Lep) and leptin receptors (Lepr), a peptide hormone of adipose tissue responsible for regulating energy metabolism in the body. According to studies by endocrinologists, an increase in the mammary glands in a child in almost 80% of cases is observed when his body weight exceeds the average age by 9-10 kg.
Experts call the following causes of diseases of the mammary glands in a child, as well as their pathological development:
The mammary glands in obese children of both sexes are often enlarged; in this case, a tumor may form, consisting of fat cells surrounded by connective tissue - breast lipoma.
In boys of puberty (over 12 years old), there is an increase in the mammary glands, which is called juvenile gynecomastia. Its cause lies in the age-related increase in the production of follicle-stimulating hormone (FSH) by the pituitary gland. As a result, there is a temporary imbalance of sex hormones, which eventually disappears.
Pain in the mammary glands in a child, as well as hardening of tissues in the nipple area, can be the result of even the most minor injury.
In adolescent girls, against the background of hormonal instability characteristic of this age, fibrocystic and hyperplastic changes in the breast can be detected:
The prognosis for most benign varieties of fibrocystic mastopathy is favorable. However, with a significant proliferation of epithelial tissues of the mammary gland, there is a threat of malignant degeneration of neoplasia.
In pediatric practice, breast cancer in a child is diagnosed extremely rarely. Most breast problems in childhood are benign breasts and many resolve without specific treatment.
However, there is juvenile secretory carcinoma, a rare form of the disease, most often diagnosed in adolescent girls. Secretory carcinoma of the breast is a special variant of invasive ductal carcinoma that occurs in juvenile patients. It develops slowly in the form of small, poorly defined by ultrasound, single or multiple nodular neoplasia (0.5-3.5 cm in size) in the ducts of the mammary glands. The peculiarity of this type of tumor is periodic secretory secretions from tumor cells; also in neoplasms there may be microcalcifications.
Breast cancer in a pubertal child in the form of phyllodes cystosarcoma is also a rare diagnosis. But this is a very aggressive tumor that captures both the parenchyma of the breast and its skin.
There are other types of cancer that can spread as metastases to breast tissue, such as lymphomas that affect the lymph nodes in the chest and armpits; leukemia, soft tissue sarcomas, neuroblastoma, etc.
The causes of breast diseases in a child in case of detection of oncology are often associated with both hormonal jumps in adolescence and maternal predisposition, in particular, mutations in the BRCA1 and BRCA2 genes. According to the American National Cancer Institute (NCI), BRCA1 mutations increase the risk of developing breast (and ovarian) cancer by 55-65%, and BRCA2 mutations by 45%.
Let us briefly list the typical symptoms of diseases of the mammary glands in a child.
With mastitis in newborns, there are: an increase in the mammary gland with a zone of compaction of subcutaneous tissues; hyperemia; soreness; high body temperature (up to +38°C); there may be a deterioration in appetite, gastrointestinal disorders (vomiting, diarrhea). With the development of an abscess, the temperature reaches + 39 ° C, a purulent infiltrate forms in the area of redness, the child is inhibited and refuses to breastfeed.
Juvenile gynecomastia in boys is characterized by: swelling of the mammary glands similar to edema in children that occurs below the nipples - with increased sensitivity of the nipples. And with gynecomastia associated with hypogonadism, painful seals form in the boy’s mammary glands, and there are also symptoms such as underdevelopment of the secondary genital organs, excess adipose tissue in the upper body, pallor of the skin, lethargy, sleep disturbances, etc.
Symptoms of fibrocystic pathologies and hyperplasia of the mammary gland in adolescent girls can manifest themselves in the form of: swelling of the mammary glands after the completion of menstruation, a feeling of fullness in the chest, swelling and mastalgia (soreness of varying intensity), the presence of elastic or firmer round nodules in the breast tissue, or elongated (cicatricial) neoplasia. With fibrous pathologies, formations form in the upper quadrant of the gland (closer to the armpit). Larger formations can lead to a change in the shape of the glands or their asymmetry. In the affected area, the color of the skin may change, and liquid discharge from the nipple is possible. In the presence of cysts, which in adolescent girls are localized under the nipple, often the skin in the areola area has a bluish tint.
It should be borne in mind that in many cases these pathologies occur without pronounced symptoms, and neoplasia is detected quite by accident.
Breast cancer in a child can manifest itself with almost the same symptoms. In addition, often discomfort and soreness can be felt in the armpit, the nipple is slightly drawn into the areola, and the skin on the chest can look like an orange peel.
Clinical diagnosis of breast pathologies in children is carried out on the basis of an examination, which begins with a physical examination of the child and the collection of anamnesis (including family history).
To determine the level of hormones in the blood serum (such as estradiol, prolactin, testosterone, LH, FSH, 17-OPG and DHEA-S, gonadoliberin, somatropin), it is necessary to take a biochemical blood test. Blood is also examined for AFP - a marker of germ cell tumors alpha-fetoprotein and markers of tumor growth.
By appointment, not only an ultrasound of the mammary glands for a child is performed, but also an ultrasound sonography of the thyroid gland, adrenal glands and pelvic organs. Mammography is not available for children.
Differential diagnosis of pathologies of the mammary glands in children is carried out using computed or magnetic resonance imaging of the adrenal glands and brain structures: the pituitary gland, hypothalamus, pineal gland.
With fibrocystic and hyperplastic changes in the mammary glands - to exclude oncology - a fine-needle aspiration biopsy of the formation (or axillary lymph node) is performed with a histological examination of the obtained biopsy.
The same treatment for all diseases of the mammary glands in a child is impossible, and therapeutic methods are determined by a specific diagnosis.
So, swelling of the mammary glands in children in the first months of life does not need treatment, but with purulent mastitis, antibiotics and sometimes abscess drainage (which is performed by a surgeon in a hospital) cannot be dispensed with. And the best prevention of mastitis in infants is perfect cleanliness and proper care of the child.
Treatment of early development of the mammary gland (thelarche) does not require treatment. However, any changes in girls' breast size should be monitored.
An increase in the mammary glands in a boy also requires observation, and if juvenile gynecomastia does not go away spontaneously a couple of years after the diagnosis is made, then the endocrinologist, based on the results of the analysis for the level of hormones in the blood, will prescribe treatment with hormonal drugs and recommend wearing a bandage on the chest.
With excess adipose tissue, its pumping (liposuction) can also be used.
Mastopathy in girls during puberty should be treated by a pediatric gynecologist or mammologist. But other specialists can also come to the rescue, since the etiology of cystic formations is associated with the thyroid gland, and breast hyperplasia in a child may occur due to neuroendocrine pathologies and disorders of the hypothalamic-pituitary-gonadal system.
In oncology, the treatment of diseases of the mammary glands in a child is carried out in the same ways as in adults (surgically, chemotherapy).
Doctors say that with timely seeking medical help, the prognosis of most pathologies of the mammary glands in children is positive. But their prevention has not been developed to date.
Anatomy will help to understand the structure and origin of the mammary glands. The mammary gland is a modified sweat gland developed from the ectoderm. In humans, the development of the mammary glands occurs in the sixth week of intrauterine life. In the area of the mammary glands, the skin is thin, delicate, contains hair follicles, sweat and sebaceous, there are many nerve fibers from the brachial and cervical plexus and intercostal nerves. The body of the gland has a discoid convex shape, the color is usually pale pink, dense texture, the average diameter at the base is 10-13 cm. The mammary glands in girls have an average weight of 150-200 g, and during lactation - 400-900 g. In most healthy young women, the glands are hemisphere-shaped and elastic. The structure of the mammary gland, size, shape and position have individual characteristics and features.
The structure of the mammary gland and its anatomy
The female mammary glands are made up of many milk-producing cells, which are assembled into lobules. A milky stream departs from each individual lobule, and all lobules are combined into segments having an excretory duct, in which all terminal small ducts are combined.
The lobes are located radially relative to the nipple and are separated from each other. Each lobe of the gland has the shape of a cone with a apex at the nipple, where the excretory duct opens. The ducts in front of the nipple expand, thus forming the lactiferous sinuses. The formed area around the nipple is called the areola, and the small elevations on it are the sweat glands. The structure of the mammary gland in women differs from the structure of the male gland.
The growth of the mammary glands is carried out due to prolactin (hormone of the anterior pituitary gland) and ovarian hormones. Thanks to prolactin, lactation occurs. In the first half of pregnancy, the breast increases in size, and in the second half there is an increase in the secretory activity of epithelial lobular cells, which consist of alveoli. At the end of pregnancy and for several days after childbirth, secretion increases and a yellowish, thick nutrient fluid called colostrum is produced. Then there is a change in the composition of the secret, it acquires a more liquid consistency and secretes milk. By the end of the feeding period, milk production decreases and stops until the next pregnancy.
The development of the mammary glands in girls occurs during puberty at the age of 10-15 years. The process begins with the growth of the nipple and areola, then the growth of the mammary gland as a whole begins. The breast in women grows for a long time and the size of the breast is finally fixed only after feeding the child. The penultimate stage of breast growth reaches the age of 15-17 years.
The mammary gland is a labile organ, just like the uterus, subject to cyclic modifications. Before the onset of menstruation, the glands proliferate, the tissues swell, the gland becomes edematous and friable. After the end of menstruation, these manifestations disappear. In accordance with age periods, the mammary gland is divided into 4 types.
As mentioned above, the structure of the mammary gland directly depends on age, the level of development of the genital organs, on the woman, hormonal status, gestational age and lactation. Age is the main factor that determines the structural type of glands. But, nevertheless, there is individual variability in the reduction and development of glandular elements, which are determined by alimentary, endocrine and other factors.
Breast development is a long process that begins at puberty and ends with the end of lactation. With the onset of puberty, secondary sexual characteristics are formed. In puberty, the breast acquires its final size and shape. Consider all the stages of development of the female bust in order to understand how the mammary glands are formed, and we will understand how the breasts grow.
The growth and development of the bust is influenced by many factors: from heredity to ecology. At some stages of growth, the increase in the mammary glands is clearly visible, at other periods, growth occurs gradually. In total, there are five successive stages during which tissues are formed.
There are five main stages. The boundaries between them are very conditional and depend on the individual characteristics of development. Everyone knows that even in puberty, girls can enter at different ages.
Development stages:
The initial stage continues from the moment of birth and lasts approximately 10 years. The breast of a newborn girl differs from the male breast in the presence of a milk line. This is a barely noticeable line that is below the nipples. It is from these tissues located along the mammary line that the mammary glands will develop during puberty. At the initial stage, no visible changes in the tissues occur.
Around the age of 13, the first visible changes begin. The breast slightly increases, the nipple darkens, the areola expands. In this state, the breast is before the onset of puberty, before the first changes in the hormonal background. Only in the pubertal period does a full-fledged glandular tissue develop.
The onset of puberty usually occurs at 13-14 years of age. Depending on the individual characteristics of the body, puberty can begin at 9 or 15 years.
Breast formation occurs for the most part just at the beginning of puberty:
The establishment of the final menstrual cycle is observed. Along with the formation of the bust, the frequency and nature of menstruation can change, this is a normal physiological process.
Puberty is completed approximately 4-5 years after the onset of the first menstruation, at the same time the formation of the breast is completed. During the entire puberty, the breast actively grows, the milk ducts develop. You need to know that throughout the development of the mammary glands, discomfort and discomfort can be observed. It is associated with active tissue growth.
By the end of puberty, the breast is considered to be formed. It takes a rounded shape, the milk ducts and lobules of the mammary gland are quite developed. At the age of 17-18, the mammary glands stop growing (except for pathology), so the breast acquires its final size.
Doctors agree that the final mammary glands develop only after pregnancy and breastfeeding. A girl who did not bear a child does not have developed glandular tissue.
At the end of puberty, the breast acquires a characteristic shape and size, the lobules of the mammary gland and the milk ducts develop. But during pregnancy, the ducts increase, additional lobules of glandular tissue appear, and the mammary gland begins to fulfill its biological function.
The full formation of the mammary glands is completed after lactation. During pregnancy, changes begin from the very moment of fertilization of the egg.
Changes that occur to the mammary glands during pregnancy:
In addition, the shape of the nipple and areola often changes during pregnancy.
Not to mention aging. The last stage of development is called involution. This is the stage of reverse development, when the sexual functions of the body fade away. This period occurs after 40 years, shortly before menopause.
The following changes take place:
The aging process continues after menopause.
The size and shape of the bust is an individual feature of the body. They are very different for different girls. The fact is that many factors influence the formation of the mammary glands. Of course, you can not take into account all of them, but you can pay attention to the main ones.
Breast growth in girls is affected by:
Heredity is the main, but not the only factor. Genetics largely determines both the health and appearance of the bust. If close relatives had large breasts, then with a high probability their daughters and granddaughters will also be able to boast of a magnificent bust.
The size is influenced by the concentration of estrogen during puberty. If there is little estrogen, then the development of the mammary glands will move more slowly. Weight and diet are important, for the full development of tissues, a complete balanced diet is required. It is necessary that the body of a teenager receive all the nutrients: vitamins, minerals and trace elements. But overeating is just as bad as undereating.
Interestingly, the size depends on the nationality. People with dark skin on average have a bust size larger than those of the inhabitants of the northern European region.
Not only the volume is important, but also the shape. Exercise will help keep it going. Muscles can be pumped so that the bust will look more elastic. In the process of formation of secondary sexual characteristics, the ecological situation is important. Smog and emissions have been proven to slow down puberty.
If you are reading these lines, we can conclude that all your attempts to combat chest pain were unsuccessful ... Have you even read something about medicines designed to defeat the infection? And this is not surprising, because mastopathy can be deadly for a person - it can develop very quickly.
Bust growth is a process that has a large number of individual characteristics. To support the body during puberty, it is enough to adhere to a healthy lifestyle.
bolivgrudi.ru
In girls, the development of the mammary glands goes through a number of successive stages. Within the specified period, their breasts are formed and completely similar to the breasts of women. This applies not only to the appearance, but also to what functions the mammary glands receive, for example, breastfeeding. About what are the features of this process - further.
The growth of the mammary glands, which is noted in girls, is scientifically called thelarche. It will last for several years, which implies the observance of some successive, from a physiological point of view, stages. At the same time, mammologists pay attention to the fact that the size and shape of the mammary glands in both boys and girls are inherited. Thus, to have a significant impact on the size simply will not work.
At the same time, an aggravated state of health or an excessively high body index at the stage of puberty can have a certain effect on this process. Experts point out the following major stages in the process of changing the mammary glands:
It is during the period that was indicated last that the woman's breasts are finally formed. Experts give various versions that are associated with the stages of development of the mammary glands.
However, in general, all mammologists and other scientists agree that at the age of 10 to 17-18 years, we can say that the breasts in girls change most actively.
A variety of factors can accelerate such changes, in particular, we can talk about hormonal disruptions, early pregnancy or the onset of sexual activity. In this regard, each case in the formation of the mammary glands, especially in the youngest girls, must be studied in a separate order. Only in this case it will be possible to clearly explain all genetic and other physiological mechanisms. It should also be noted that the fundamental changes associated with the region of the mammary glands should be controlled by a specialist. This is necessary for the full provision of all life processes and their correctness, which is very important for girls.
The process of changing the mammary glands begins with the areola and nipple region. At this time, they greatly increase in size and, at the same time, under them, an increase in the size of the gland itself is noted. Experts pay attention to the fact that the area in which the nipple and areola are located, depending on the shade of the skin and race, can change its color. We are talking about the fact that the initial should be considered a pale pink with an insignificant brown tint, while the most distinct is brown with a very rich palette. In girls, this feature can be inherited not only from the mother, but also from the father - this should also be taken into account by young parents.
It must also be remembered that:
In this case, we are talking about glands that secrete a specific skin secret. It is necessary to lubricate the nipple and areola area so that the skin on them does not crack and also does not dry out. These parts of the mammary glands will play a special role during breastfeeding.
Without a doubt, the mammary glands are a special organ and part of the female body, which literally requires special attention to itself. In this regard, throughout life, it is recommended to remember that it is necessary to monitor the stages of its development and general condition, to carry out an independent examination and other equally necessary diagnostic measures. Also, speaking about breast development in general, I would like to note other nuances that are extremely important for understanding the processes occurring in girls.
The mammary gland is such an organ, which, as you know, directly depends on hormones and their ratio. In this regard, the region of the mammary glands can respond to changes in the body related to the hormonal background. For example, mammologists point out that a change in the overall size of the mammary glands before the menstrual cycle can be identified, the breast can be much more susceptible and even painful. In the vast majority of cases, these changes are formed not in girls, but in older women who have already encountered some diseases of the thyroid gland and the reproductive system. The presence of such signs in young women should be considered a very alarming manifestation, indicating dysfunction of the mammary glands.
It must be borne in mind that if these changes in the mammary glands are pronounced, and are also combined with other objectively unpleasant manifestations, this may be the main symptom of premenstrual syndrome. This process is a specific state that is directly related to hormonal metabolism.
To exclude or mitigate this process, it is strongly recommended to seek specialized advice from a specialist gynecologist.
It is he who will make it possible to select all the necessary components to alleviate pain and discomfort. Speaking of young girls, it should be noted that they traditionally choose special herbal preparations and whole complexes of vitamin components with minerals. In the case when the pain is strong, it may be necessary for a much more serious correction.
Mammologists pay attention to the fact that in girls and subsequently women, such organs and systems as the endocrine gland, mammary glands and reproductive organs are extremely closely interconnected. Problems in any of these areas can adversely affect the work of these organs and, as a result, provoke problematic development of the mammary glands. In order to avoid this, it is necessary to have the most complete and up-to-date information about what thelarche is, what are its stages and what physiological changes girls will face. This is what will make breast development as correct and “healthy” as possible.
Important!
BREAST CANCER IN WOMEN APPEARS MORE AND MORE! TAKE THE TEST AND FIND OUT WHETHER IT IS DANGEROUS FOR YOU!
0 of 11 tasks completed
It's completely free and only takes a couple of minutes!
You have already taken the test before. You cannot run it again.
You must login or register in order to start the test.
You must complete the following tests to start this one:
Your time:
Time is over
Do not forget to periodically be observed by a mammologist! These visits will help YOU prevent the risk of cancer!
Determining the risk of breast cancer
This test retains the reliability of calculations for a Caucasian woman, with no identified genes for heredity for breast cancer, without a previous diagnosis of this disease, and subject to an annual examination by a mammologist.
The risk of getting breast cancer within 10, 20 and 30 years is -0.1%, 1.1%, 3.2% respectively.
The probability of not getting sick for 10, 20 and 30 years is 100.1%, 98.9%, 96.8%, respectively.
This test is not quite suitable for girls under 20 years old and women over 50 years old (there may be small errors). We advise you to read the materials prepared by us about the structure of the breast, risk factors for breast cancer and breast self-examination skills that every adult woman should know.
vgrudi.ru
Breast development is a vital process in the formation of the female reproductive system. It is impossible to say exactly how old the breast grows. The size and shape of the mammary glands are strongly dependent on weight (the amount of adipose tissue), hormone levels and heredity.
Girls' breasts begin to change during puberty. It responds to the phases of the menstrual cycle, increases markedly during pregnancy and lactation. Certain changes in the breasts also occur when a woman reaches the age of menopause.
Unlike the mammary glands of female mammals, a woman's breasts begin to develop long before she needs to feed her baby.
The chest is made up of:
It is important to note that small and large breasts can produce the same amount of milk after the onset of lactation to feed an infant.
Many girls in puberty begin to worry about why their breasts do not grow or why their mammary glands develop much faster than their peers. It should be remembered that physiology depends on heredity and the activity of hormones during growing up. The size, shape of the mammary glands and nipples, as well as their pigmentation, can be very individual. Usually, girls' breasts develop in the same way as their closest relatives: older sisters, mothers or even grandmothers. This is a good guide to understand when the breast will grow, what shape and size it will be.
Formation according to the female type begins in the mother's womb in the second month of the life of the embryo. After birth, girls have already formed nipples and rudiments of the milk duct.
Sometimes during breastfeeding, the baby's nipples may swell, become more dense. A clear liquid is secreted from the mammary glands - a secret. This happens under the influence of prolactin, a female hormone that enters the body of a newborn along with mother's milk.
Such a change in the nipples is natural if the swelling of the mammary glands is not accompanied by:
Girls begin puberty at 9-10 years of age or later. Sometimes puberty begins earlier, at 7–8 years. There is nothing wrong with this, but such an earlier development is more characteristic of girls from southern countries with a hotter climate.
As girls approach puberty, the ovaries begin to produce the hormone estrogen. Secondary sexual characteristics appear, such as pubic and armpit hairs. Almost simultaneously with this, the milk ducts increase, the breast begins to fill with adipose tissue.
The first signs of the onset of mammary gland development are swelling of one or both nipples. Usually these are small seals - the so-called "buds". As soon as the girls begin menstruation, the "buds" ripen:
From the beginning of adolescence, girls' breasts go through several noticeable phases of development.
In adolescence, the mammary glands complete the most significant stage of their formation. However, the shape and size can change at an older age under the influence of hormones. Especially noticeably, the breast begins to grow during pregnancy and lactation.
Every month, a woman experiences hormonal changes that trigger a period of ovulation and menstruation for healthy reproductive function.
Both of these hormones, estrogen and progesterone, make the breasts swollen and tender in the days leading up to a period. During the menstruation itself, seals can form in the breast - these are enlarged glands prepared for a possible pregnancy. If the egg is not fertilized, the breast returns to its normal size.
Many experts believe that the final formation of the female breast occurs only during motherhood. Breast changes are one of the earliest signs of pregnancy. In the first weeks, women feel that their breasts have become swollen, start to hurt, and the sensitivity of the nipples has increased. This happens as a result of the fact that progesterone begins to expand the milk ducts and form new lobes of the mammary glands.
At 5-6 months of pregnancy, the breast is completely ready for lactation. Changes during childbearing provoke hormones such as:
Also, in pregnant women, the areola around the nipple darkens, the network of blood vessels begins to clearly appear. These are all stages of preparation for feeding a newborn.
After the end of lactation, the breasts may return to their previous size, but most often the size and shape of the mammary glands changes, especially in women with a magnificent bust.
The period of menopause begins in women at 45-50 years or a little later. At this age, the hormonal level becomes unstable, the amount of estrogen in the body decreases significantly. Without estrogen stimulation, the mammary glands decrease in size. All the connective tissues of the body become inelastic and dehydrated, which causes the breasts to sag and begin to look characteristic of women of a more mature age group.
grudplus.ru
The breast is a symbol of beauty and sexuality for every woman. But still, its main function is to feed the born baby. Therefore, the structure of the mammary gland is designed so that mommy performs this function, conceived by nature.
Structural components of the breast
1. Glandular
2. Connective tissue
3. Fatty
The ratio of these components varies depending on the age of the woman, but all three must be present.
Thus, studying the structure of the breast in such a section of the gland, we see in layers (now from the right to the left): the premammary fat layer, the glandular tissue and the retromamarary fat layer, and then the muscles that are not directly related to the chest.
In the structure of the mammary glands of a woman, we will consider in more detail such components of the structure as the glandular tissue of the mammary gland and connective tissue.
Forms the working part of the chest.
Any mammary gland consists of 6 - 8 lobes - a small breast, and 20 - 25 lobes - a large gland. They are going to the nipple radially and can overlap each other. Each lobe is surrounded by connective tissue, as well as a small amount of adipose tissue. The shape of the lobe is cone-shaped, with the apex at the nipple.
The glandular lobule does not have an outer capsule. The bulk of the glandular tissue is in the upper outer quadrant of the organ. And all kinds of tumors are formed there.
An excretory milk duct (galactophore) departs from each lobule.
Classification of ducts according to the movement of the secret
1. Galactophore of the 1st order - the duct leaves the lobule. Its diameter is about 1 mm.
2. Galactophore of the 2nd order - located inside the lobe and larger - 2 mm.
3. Galactophore of the third order - flows into the lactiferous sinus, which is turned towards the nipple, the size of the duct is up to three mm.
With histology, we see such a picture on the cut
With the microscopic structure of a normal mammary gland, white spots are visible - this is adipose tissue located in the gaps. With age, it becomes more and more, the glandular leaves, and the fatty one replaces it.
It is represented by 2 components:
1. Coarse, fibrous (fascial), depicted in red. The superficial fascia of the chest descends from the top down from the collarbone, at the level of the second or third rib, it is divided into 2 leaflets. One of them becomes a surface leaf, and the other becomes a deep one.
And these 2 leaflets clasp the glandular part of the chest (adipose tissue is located in front and behind this leaflet). It is like a natural bra that suspends the glandular tissue. But they do not close in the nipple area and, as it were, let these excretory ducts pass.
Cooper's ligaments extend from these fascia inward (into the glandular tissue) and outward (into the skin), which divide the glandular tissue into separate fragments and, when palpated, these septa determine the gland not as a single mass, but as separate fragments. Because of this, the areas between the ligaments during palpation are often incorrectly interpreted.
These Cooper's ligaments are especially well felt in the childbearing period, when the glandular and adipose tissue are balanced.
The mammary gland is one of the organs most often affected by cancer and is often sent for research due to the fact that when probing, the doctor found some kind of heterogeneity, confusing it with Cooper's ligaments, which divide the gland into separate fragments.
2. Lodge (mantle) fabric. Between the lobules fibrous tissue, supporting. And inside the lobule there is a bed tissue, which contains almost no fibers, but has a large number of cells (unlike the supporting one, where there are many fibers and few cells).
Each lobule is immersed in mantle tissue. She, like a mantle, immerses each segment and share as a whole.
Over time, the underlying tissue is replaced by fibrous tissue. Those. a transformation occurs - the cells leave, and the fibers become larger. And this process is similar to the formation of cellulite on other areas of the body. it is a derivative of the skin - and the mechanism is the same.
Cellulite is not just the deposition of more fat in the subcutaneous layer than it should be, but a violation of the structure of fibrous tissues. They lead to orange peel because instead of a connective tissue containing cells and few fibers, a large number of fibers form, which pulls the skin, dividing it into separate fragments.
Women who smoke for 5-7 years, the connective tissue is replaced by fibrous tissue much faster and fibrocystic mastopathy occurs, which is clearly visible on ultrasound. If normally it takes 20-30-40 years, then when smoking it develops disproportionately much faster.
By the age of 70, women have very little mantle tissue, and a lot of coarse fibrous tissue, and this is a normal physiological process. And with adverse factors, this process can be aggravated. And if there is a lot of fibrous tissue, the ducts will be compressed and cysts will form.
1. Prenatal phase
It begins at 8-10 weeks of embryo development in the form of 7-8 paired primordia along 2 milk lines. Those. on the ventral side of the embryo, 2 lactiferous lines are formed, running from the inguinal region to the axillary regions. And all this ends with the formation of a rudimentary organ, consisting of simple branching ducts, on which there are no segments yet (as on trees in winter - there are branches, but no leaves, they will grow later).
But already these cells can respond to the hormonal effects of the mother's body by forming a secret inside.
These lines are laid in parallel, then they undergo reverse development, except for 3 or 4. The mammary gland is formed by 3 or 4 milk points, and the rest undergo a rudimentary change, and then, as a rule, even before birth, disappear. This also applies to men, too, that they form mammary glands.
If the process is disturbed, then there may be polythelia - additional nipples. They look like birthmarks. There is no glandular tissue. And when it is, it is called polymastia.
It often happens that an axillary lobule is formed - there is no nipple, but there is glandular tissue. Often this appears during the first feeding of the child, when secretory stimulation occurs and it swells.
2. Pubertal phase
The process of elongation and branching of the ducts, which ends with the formation of the final lobules.
The first sign is the development of the mammary glands (thelarche). It may coincide with pubarche - the growth of pubic hair, or maybe earlier.
1. Prepubertal - children's
2. Clinically appears as a palpable subareolar kidney before it becomes recognizable as an elevation.
3. Manifested by obvious enlargement and elevation of the entire breast (usually initially on one side)
4. Areolar protrusion phase (transient stage, which may not appear)
5. Achieving the contour of a mature breast (often asymmetrical).
The asymmetry of the glands may be due to the delay of one of them in the third or fourth stage according to Tanner.
Options for the normal development of the mammary glands
Initial development of the organ on one side (can clinically simulate a tumor)
Unilateral development may take place up to 2 years before the onset of development of the second gland.
Premature thelarche
Two weeks before menstruation, the mammary glands hurt
2018 Women's Health Blog.
