At what age does puberty begin and end?

Adolescence refers to the stage when an individual's sexual function changes from immaturity to maturity. In biology, it refers to the transition period from immaturity to maturity, that is, the transition period from children to adults for men. During this period, my personality is mature and I can have children. It can be seen that adolescence is mainly a stage of physiological maturity, which overlaps with the stages of life divided from psychological or social aspects. In the stage of human growth and development, adolescence accounts for half or even more time. At present, there is no consistent age range in various countries, which generally refers to 13, 14-17 and 18 stages. Psychologically, it is also called pre-adolescence, which is equivalent to the middle school stage in pedagogy and is characterized by rapid physical growth. In addition to adolescence, adolescence will last until the age of 25-30. Because the sexual maturity of men is about one year later than that of women, it can be determined that the puberty age range of men is 14- 18 years old. 1 ~ 2 years too early or too late is normal. Men of this age are usually called boys, while women of the same age are called girls. In adolescence, there are not only obvious physiological changes, but also great psychological changes.

Physical growth with sexual maturity as the main content has a great influence on the psychological and social aspects of teenagers, forming several important characteristics of this period:

Adolescence is a transitional period.

Adolescence is the transition period from children to adults. Usually, people clearly distinguish between adolescence and childhood, and the dividing line is sexual maturity. For men, the sign of sexual maturity is ejaculation (usually ejaculation during night sleep, that is, nocturnal emission, but also masturbation ejaculation); Women have menarche, that is, the first menstruation. The physiological development centered on sexual maturity makes teenagers have obviously different social and psychological characteristics from children. Individuals depend on adults in childhood, and adults constrain and decide the main contents and aspects of children's lives and activities; Children are not responsible for their actions. With the increase of age and the complexity of life scope and activities, teenagers have different characteristics from children. They gradually have a certain intention and sense of responsibility, and decide how to carry out certain activities by themselves. You should bear certain criminal responsibility for your actions, especially some criminal acts. But teenagers are also different from adults. Although they have some independence, they are not completely independent; In many ways, especially in material life, we have to rely on our parents; They have not yet become fully responsible persons and are not criminally responsible for all their actions. It can be seen that this transitional state between children and adults makes teenagers become marginalized people in sociology. The uncertainty of their identity and the uncertainty of social demands on them have caused many special mental health problems.

Adolescence is a period of development

Adolescence is a period when a person's physical development is completed. Research shows that there are two stages in a person's life: the rapid growth of the body and the significant changes in the proportion of various parts of the body. One is in the prenatal period and the first half year after birth, and the other is adolescence. The rapid growth and development of adolescence is called the phenomenon of rapid growth of adolescence. In fact, this phenomenon begins before or at the same time as sexual maturity and ends six months to one year after sexual maturity. The rapid growth of men began at the age of 10.5- 14.5, peaked at the age of 14.5- 15.5, and then gradually slowed down. By the age of 18, the height has reached a fully developed level, and the weight, muscle strength, shoulder width and pelvic width have also increased. For example, while women are experiencing external changes such as menstruation and secondary sexual characteristics, the reproductive organs gradually mature, pubic hair begins to appear in the vulva, vaginal secretions begin to increase, the uterus becomes larger, and follicles in the ovarian cortex begin to develop at different stages. Everything shows that the transition to sexual maturity has begun. Due to the physical and sexual development, it has a great influence on the psychological characteristics and social life of teenagers, which also produces a series of mental health problems.

Adolescence is a period of change.

Adolescence is the most rapid and obvious period of physical and mental changes of teenagers. During this period, men are divorced from the characteristics of children in terms of body, appearance, behavior, self-awareness, communication and emotional characteristics, and outlook on life, and gradually become mature and close to adults. These rapid changes will make teenagers have mental health problems such as confusion, inferiority, anxiety and even bad behavior. Therefore, adolescence is a predictable and unpredictable period. That is to say, in this period, the development of people from children to adults is predictable, but what will happen or what problems will occur in the development process is unpredictable.

Adolescence is a period of resistance.

In the early days, the famous German child psychologist Charlotte Buller once called adolescence "a period of passive resistance". This name has been used to this day. Due to the gradual development and maturity of body and mind, individuals often take a negative and rebellious attitude towards life during this period, denying some good qualities they have developed before. This rebellious tendency will make teenagers resist other requirements and norms of parents, schools and social life, which will lead to some mental health problems that are not conducive to their social adaptation.

Adolescence is a period of heavy burden.

Judging from the obligations and responsibilities of adolescent men and the problems they have to deal with, adolescence is also a period of heavy burden. Adolescence is a transitional period. Teenagers should gradually undertake some tasks undertaken by adults, and the environment may constantly hand over some things handled by adults to them, which will increase their burden, but these burdens are indispensable for their maturity. If they are not burdened, they will not mature in the future. Adolescence is a developmental period, which determines that they have to deal with various changes and problems brought about by the maturity of height, weight and muscle strength. Especially when they are sexually mature, their psychological pressure increases relatively fast. Adolescence is a period of change, which determines that they must abandon all kinds of childish ideas and behavior patterns, and gradually establish more mature and more in line with social norms. Adolescence is a period of resistance, which determines that we should try our best to maintain and protect the normal relationship with society while coping with our own resistance tendency. In addition, heterosexual interests, heterosexual communication, and heavy learning tasks. It also causes great burden to their body and mind, and sometimes even becomes the main contradiction.

Physiological characteristics of female adolescence

For women, adolescence refers to the period from menstrual cramps to the gradual development and maturity of reproductive organs. Generally from 13 to 18.

The physiological characteristics of this period are the rapid development of body and reproductive organs, the formation of secondary sexual characteristics and the beginning of menstruation. ① General development: With the arrival of adolescence, the whole body grows rapidly and matures gradually. ② Development of reproductive organs: With the gradual increase of ovarian development and sex hormone secretion, there are obvious changes in various parts of the genitals, which are called primary sexual characteristics. The external genitalia changed from infant type to adult type, with swollen pubic mound, thickened labia majora, enlarged labia minora and pigmentation, increased vaginal length and width, thickened vaginal mucosa and wrinkles. The uterus is enlarged, especially the uterine body is obviously enlarged, so that the uterine body accounts for 2/3 of the total length of the uterus; Tubal thickening and curvature reduction; The ovary is enlarged, and there are follicles at different stages of development in the cortex, which makes the surface slightly uneven. ③ Secondary sexual characteristics: refers to the unique signs of women except reproductive organs. At this time, the girl's tone becomes higher, her breasts are plump and bulging, and armpit hair and pubic hair appear. The development of transverse diameter of pelvis is larger than that of anteroposterior diameter, and there is more subcutaneous fat in her chest and shoulders, which shows the unique posture of women. Menstruation: Menstruation is an important sign of adolescence. Because the ovarian function is not perfect, the menstrual cycle after menarche has no certain regularity, and it must be gradually adjusted to get close to normal.

Adolescent physiology changes greatly, and thoughts and emotions are often unstable. Families and schools should pay attention to their physical and mental health.

Physiological characteristics of male adolescence

The transition from childhood to adolescence is "the second birth of life", which psychologists call "the second crisis". If the first crisis of life-"weaning crisis" is spent in a warm infancy, the child's resistance is at best a powerless struggle and hopeless crying. Then, the second crisis of life-the psychological "weaning" of being mentally separated from parents, came quickly and unstoppable. At this time, a series of significant physiological changes will occur in the body, which is the best period for male growth and development. There are great changes in both morphology and physiology. In addition to the sharp increase in height and weight, it is mainly the development of secondary sexual characteristics, such as the thickening of voice, the appearance of beard and armpit hair, the gradual development of reproductive organs, the growth of pubic hair, the enlargement of testicles and penis, the maturity of gonads and the beginning of nocturnal emission. Personality has also become mature, sophisticated, steady and confident, no longer as naive and ignorant as children.

So, how does adolescence begin? Recent studies have shown that it is regulated by a physiologically active substance called gonadotropin in human body, which affects development and makes it secrete sex hormones to maintain the development of secondary sexual characteristics and reproductive and sexual functions. At the beginning of male puberty, the level of gonadotropin PSH increases, which promotes the gradual development of testis, the development of seminiferous tubules, the maturation of spermatogenic cells and the production of sperm. At the same time, the level of gonadotropin CH also increased, which promoted the development of leydig cells in testis, produced testosterone, and promoted the further development of male reproductive organs and the development of secondary sexual characteristics.

The arrival of adolescence marks the beginning of a man's development to adulthood. He will be a mature individual with reproductive offspring to continue his racial life. This is the most important period in a man's life, which is closely related to society, family education, personal life growth and mental state. When a man reaches puberty, due to the maturity of sex education, under the action of androgen, he will have sexual demands and love for his wife, which is a psychological change accompanied by physical development in the process of youth development and is a normal phenomenon. However, if it is not handled well, it is easy to make mistakes if it lacks proper sexual knowledge and pays no attention to sexual morality. So some people call this period "the critical period of youth".

Adolescence is also a critical period that determines the physical, psychological and intellectual development of a lifetime. Although the body's resistance is stronger than that of childhood, some infectious diseases and common diseases such as tuberculosis, hepatitis, nephritis and myocarditis are not uncommon, while the autonomic nerve (the nerve that manages the smooth muscle, heart muscle and gland activities of various organs) is dysfunctional, and sporadic goiter, hyperthyroidism and neurosis are significantly increased compared with childhood. Therefore, adolescent health can not be ignored. We should pay attention to nutrition, rest, study hard and exercise to lay a good foundation for lifelong health and work.