The whole process of adolescent girls' development

In China, the age range from 12 to 18 is generally considered as puberty. Adolescence is the second peak of human growth and development, with great changes in physiology, rapid growth in height and weight, increasingly mature functions of heart, lungs, liver and other organs, and various indicators reaching or approaching adult standards. The development of adolescent girls is first of all sexual development. Including the development of gonads (ovaries), internal and external reproductive organs and secondary sexual characteristics.

Girl 13 years old, the ovaries gradually grow up and menstruation begins. Correspondingly, the uterus, vagina and external genitalia gradually grow, lengthen and mature. These changes are generally "silent" and it is often difficult to attract people's attention.

However, as an external change of women, the secondary sexual characteristics are more noticeable: at the age of 9- 10, breasts begin to develop, which is the first time that girls show secondary sexual characteristics and is a sign of puberty germination; 1 1 year-old pubic hair; 12- 13 years old, the nipple areola continues to increase, but it still blends with the whole breast contour; Pubic hair continues to increase, developing to pubic mound and middle part of abdominal wall, from fine to thick, and pigment gradually precipitates.

What is adolescence?

Under normal circumstances, girls' puberty is about one year earlier than boys', and it takes about 2 ~ 3 years from the beginning of breast development to menarche, and then armpit hair and pubic hair grow out, the pelvis becomes bigger, and the subcutaneous fat of the whole body increases (especially in the chest and shoulders), forming a plump posture of women. The boy has a long beard, prominent Adam's apple, deep voice and solid musculoskeletal development, forming a burly physique of a man.

Adolescence is a period of rapid physical and mental development of teenagers, a period of transition from childhood to adulthood, and a critical period of gradual formation of outlook on life and world.

The menarche of girls is after 13 years old (some girls are earlier), but it is generally irregular. One or two years ago, the ovarian function was not perfect or mature enough to ovulate; At the same time or later than menarche, armpit hair grows, pubic hair is distributed in an inverted triangle unique to women, and the bottom is parallel to pubic symphysis; The glands in areola area develop, forming a second bulge on the plump and enlarged breast; 14- 15 years old, showing regular ovulation menstruation; The breast is mature, and the nipple protrudes from the well-defined breast; 16- 17 years old, the development is close to maturity, the bone scale heals, and the height growth basically stops.

The development of the above sexual characteristics has obvious timeliness and order. If there are time violations, such as breast development before the age of 8, or menstrual cramps before the age of 9, it is precocious puberty; /kloc-development begins after 0/6 years old, which is called puberty delay; /kloc-after the age of 0/8, he is still naive, which may be sexual hypoplasia. It is often idiopathic precocious puberty, or true precocious puberty caused by brain lesions, or false precocious puberty caused by taking estrogen-containing drugs, food and ovarian tumors by mistake, or congenital diseases and ovarian dysfunction caused by delayed gonadotropin. These must be diagnosed and treated in time.

More attention should be paid to the disorder of sexual development order, such as menstruation comes before breast development and pubic hair growth; Or the breast has not yet developed, and the armpit hair and pubic hair grow prematurely. It must be an abnormal performance. Go to see a doctor quickly.

The second is the "acceleration" of physical growth

Height growth begins earlier than breast development, and most of them reach the peak speed when breast tissue around areola expands. At this time, the average height increases by 8 cm every year, even reaching 10 ~ 13 cm; At the same time, the body weight also increased by 5 ~ 6 kg, most of which reached 10 kg. After that, the growth rate began to decline, and the potential to continue to grow taller after menarche was limited, generally only 3 ~ 5 cm per year. From sudden growth to stop growth, the average height of girls increased by about 25 cm. Therefore, in just a few years, the original delicate and childish girl has grown into a slim girl.

Sex organs are the latest organs in human body. Once the sexual organs are mature, it means that all organ systems in the body are mature.

The development of sexual characteristics, the growth of the body and the perfection and maturity of the functions of various organs are all dominated by the endocrine system. When girls enter puberty, gonadotropins (luteinizing hormone and follicle stimulating hormone) secreted by pituitary gland begin the prelude of sexual development, promote the development and growth of ovaries, mature follicles, produce estrogen, ovulate once a month, and command one menstrual cycle after another. If gonadotropins are active too early, precocious puberty will occur; If you are lazy, your youth will come late.

Growth hormone secreted by pituitary gland, sex hormones secreted by adrenal gland and ovary, thyroid hormone secreted by thyroid gland, etc. All of them have a unique complementary effect on bone development and height growth. As a result of the comprehensive coordination of these endocrine hormones, girls are endowed with a symmetrical figure.

The development of the breast, uterus and pudendal region, the proliferation of pelvic chondrocytes, the widening of the entrance, the enlargement of the buttocks, the proliferation of fat cells in the body and the accumulation of subcutaneous fat are all the functions of female hormones.

There are also a small amount of male hormones in women, mainly from adrenal glands, and a small amount secreted by ovaries, which promote the growth of armpit hair and pubic hair and the development of pudendum. The activity of pituitary gland is also influenced by hypothalamus and target gland organs. Of course, the levels of pituitary hormones and target gland hormones also affect the secretion function of hypothalamus and pituitary gland in turn. Hypothalamus-pituitary-target gland (mainly ovary) constitutes the control axis of eighteen changes in adolescence, which is interdependent and mutually restrictive, so that the hormone concentration in girls' blood remains relatively stable and properly meets the needs of eighteen changes in women's universities.

It is worth mentioning that higher nervous activity affects endocrine function and plays an important regulatory role in endocrine. For example, changing the environment and anxiety can cause amenorrhea and stimulate sensory organs (smell, vision, etc. ) can promote gonadal activity, and mechanical stimulation of reproductive tract can cause ovulation. In addition, genetic factors, climate and environment, culture and education, economic situation, adolescent health care and bodybuilding exercise also affect endocrine, which in turn affects adolescent development.

Knowing the "secret" of girls' puberty development will make girls' puberty "eighteen changes" more and more beautiful.