Introduction
Puberty is the phase between childhood and adulthood, in which far-reaching physical and psychological changes occur. The secondary sexual characteristics become pronounced, sexual maturity and growth spurts occur. In addition, this phase is divided into prepubertal and postmenarche.
In girls, puberty begins about 2 years earlier than in boys. Prepuberty begins around the age of 9 with the first physical changes and ends on average in the age of 13 with the onset of the first menstrual period (menarche). The subsequent period up to the age of 15, during which the monthly cycle becomes increasingly regular, is called postmenarche.
What happens in puberty?
There are many changes in the body and mind of young people. The previously childlike body develops the externally visible sexual characteristics, such as beard growth in boys and breast growth in girls. The hormonal balance of the body is also altered.
More sex-specific hormones, such as testosterone or estrogen, are produced. In boys the production of sperm starts and in girls the first menstruation occurs, which shows the beginning of fertility. In addition to the sexual characteristics, there is also a general growth spurt.
By changing the amount of fat in the skin, young people often get acne and oily hair. Psychological changes also occur. The adolescents react more emotionally to stressful situations and distinguish themselves from their parents by sometimes provocative behavior. In rare cases, these developmental steps occur much earlier or much later than normal.
Physical changes during puberty
Breast development usually goes through 5 stages. The volume of the breast as well as the size of the nipple increases steadily. The nipple initially stands out from the level of the breast, but in stage 3 it returns to the level of the breast and in stage 4 it again stands out from the rest of the breast contour.
Some women retain this breast shape, but usually the last stage of development is reached when the nipple again adapts to the rest of the breast contour. The development of pubic hair usually begins with some fuzz on the labia majora and the mons pubis and continues to spread until the typical triangular shape with a horizontal boundary at the top is created. Density and pigmentation of the pubic hair increases steadily.
The secretion of sex hormones causes a change in the body composition of boys in favor of muscle mass, in girls in favor of fatty tissue. The growth spurt is determined by sex hormones as well as growth hormones, whereby the female sex hormone estrogen accelerates this process and allows growth to stop earlier. Girls therefore have their growth spurt much earlier than boys, most pronounced before the first menstrual period.
The hormonal changes are characterized by the adrenal and gonadarche. The adrenarche represents the beginning of the release of male sex hormones from the adrenal cortex, which is manifested by the development of pubic hair. The gonadarche is the beginning of stimulation for the release of sex hormones by the pituitary gland (hypophysis) and higher-level centers.
The growth spurt is triggered in puberty by the male hormone testosterone. This hormone is also present in smaller quantities in girls and thus also leads to the growth spurt in girls. Oestrogen also has a growth-promoting effect.
The hormones have an effect on bone growth, which is why some adolescents develop pain if they grow too fast. The growth spurt is completed with the closure of the growth joints. After this closure, longitudinal growth of the bones is no longer possible.
Puberty begins in boys on average at the age of twelve years, two years later than in girls. The beginning of puberty is not yet visible to the outside and is characterized by a hormonal change in the body. This already happens at the age of about nine years.
The first visible sign of the onset of puberty is testicular growth. By definition, a testicular volume of more than three millimeters indicates the beginning of puberty. The pubic hair also begins to grow.
The penis increases in size. At about 13 years of age, sperm production in the testicles begins. The quality of the sperm only increases in the course of the following months and years.In addition to the external sexual organs, there is significant body growth and an increase in the proportion of muscle in the body mass.
Furthermore, beard growth begins, which is not fully developed until after puberty. Due to the hormonal influence, the vocal folds also change and the voice of the boys becomes deeper after this development is completed. Increased perspiration leads to body odor, greasy hair and acne.
In girls, puberty begins at the age of about ten years, two years earlier than in their male counterparts. Even in girls, the first hormonal changes are not externally visible. The body begins to produce large amounts of female hormones such as estrogen and small amounts of male testosterone.
The first physical change can be seen in breast growth. The breasts often do not grow symmetrically at first, but the difference usually evens out by the end of the development. The testosterone continues to cause the growth of pubic hair in the armpit and pubic area.
Just like their male counterparts, girls also experience a growth spurt. However, the body growth is already finished much earlier than in boys. The body takes on typically female features, like a wider pelvis.
The last step of female puberty is the onset of menstruation and thus the beginning of sexual maturity. This happens at an average age of 12.8 years and depends on the nutritional status. Just as with boys, acne and oily hairs are caused by an increased fat content in the skin.
During puberty, increased sex hormones are released. In girls these are especially estrogens, estradiol and prolactin. These hormones cause the female breast to grow.
Puberty is associated with the achievement of sexual maturity, which is why the girl’s body adjusts itself to supplying an infant. For this reason the mammary glands mature. In boys, too, an increase in breast tissue is possible during puberty.
This usually regresses after two years. In puberty the child’s body turns into an adult body. In girls this means that fatty tissue grows in the hip area.
Boys develop a larger muscle percentage. Both lead to weight gain, which is part of normal development. During puberty, the body needs a lot of energy for various restructuring processes.
If there is an oversupply of food, the body stores this energy in the form of fat so that it can fall back on it later. In girls, the accumulation of energy reserves is also associated with a preparation for a possible pregnancy. The skin of children has a high water content and a low fat content.
In puberty this ratio is changed. In the beginning, the sebaceous glands in the skin can cause an overproduction of sebum. This leads to quickly greasy hair.
With the end of puberty, a balance is usually established so that the hair does not become greasy as quickly. However, sebum production is not increased by washing. The young people can therefore easily wash their hair every day to feel more comfortable.
In childhood, sweat is almost odourless. In puberty, however, it is another way for sweat glands to work. These are located especially in the genital area and the armpits.
Teenagers sweat more than children and adults. The composition of the body sweat also changes. Sweat contains certain substances, such as urea and lactic acid, which are metabolized by bacteria on the skin. The longer the sweat is on the skin, the stronger the smell. This topic might also be of interest to you: Excessive sweating
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