The adolescent growth spurt of boys and girls of the Harpenden growth study.
Teens going through puberty will have many changes in their developing bodies The growth spurt of boys is, on average, about 2 years later than that of girls. called adolescence. During this time, the teenager will see the greatest amount of growth in height and weight. Adolescence is a time for growth spurts and puberty changes. He/she may have long-term commitment in a relationship. A A A. The human adolescent growth spurt is noted in virtually all of the long bones of Timing of appearance of the difference in the Hominin Lineage as a defined.
Next, the penis will continue to grow in both size and length. In girls, the initial puberty change is the development of breast buds, in which the breast and nipple elevate. The areola dark area of skin that surrounds the nipple of the breast increases in size at this time. The breasts then continue to enlarge. Eventually, the nipples and the areolas will elevate again, forming another projection on the breasts. At the adult state, only the nipple remains elevated above the rest of the breast tissue.
Pubic hair development is similar for both girls and boys. The initial growth of hair produces long, soft hair that is only in a small area around the genitals. This hair then becomes darker and coarser as it continues to spread. The pubic hair eventually looks like adult hair, but in a smaller area. It may spread to the thighs and, sometimes, up the stomach.
Adolescent Growth Spurt | Center for Academic Research and Training in Anthropogeny (CARTA)
What does my adolescent understand? The teenage years bring many changes, not only physically, but also mentally and socially. During these years, adolescents increase their ability to think abstractly and eventually make plans and set long-term goals.
Several factors can influence potential height such as genetics and nutrition, as do certain medical conditions and medications that interfere with digestion and appetite. During adolescent growth spurts, the arms and legs also lengthen and eventually become proportional to the rest of their body. However, teens may suddenly feel awkward and uncoordinated during this time because growth does not always occur at a perfectly proportional rate.
Their limbs may become longer or shorter relative to the rest of their bodies and it may confuse or frustrate young teens to inhabit a body that no longer seems familiar. Besides significant changes in height, adolescents also experience changes in body composition; i. Teen boys' lean muscle mass greatly increases during adolescence due to the rising levels of male hormones, such as testosterone, that cause an increase in muscle mass.
In general, boys' straight-lined, square bodies become broader at the shoulders and more tapered at the waist, forming the familiar triangular shape of adult males. Their arms and legs will become more muscular and bulkier.At what age do boys stop growing?
However, factors such as heredity, nutrition, and muscle-building exercise can influence muscular development. If adolescents play sports, lift weights, or routinely workout in other ways, they are more likely to gain muscle mass. Many teen boys may feel self-conscious about their body if they believe they are not building enough muscle in comparison to their friends and classmates. Teen girls continue to develop muscle mass while also adding body fat.
During adolescence, girls' percentage of body fat will increase, relative to muscle mass. This additional fat is deposited in her body's midsection hips, buttocks, and chest.
- How much will my adolescent grow?
- What changes will occur during puberty?
Girls' straight-lined, square bodies become wider and broader at the hips, buttocks, and chest, forming the familiar hour-glass shape of adult females. The structure has changed to resemble an adult form. Puberty is a period of several years in which rapid physical growth and psychological changes occur, culminating in sexual maturity.
The average age of onset of puberty is at 11 for girls and 12 for boys. Hormones play an organizational role, priming the body to behave in a certain way once puberty begins,  and an active role, referring to changes in hormones during adolescence that trigger behavioral and physical changes. It is the stage of life characterized by the appearance and development of secondary sex characteristics for example, a deeper voice and larger adam's apple in boys, and development of breasts and more curved and prominent hips in girls and a strong shift in hormonal balance towards an adult state.
This is triggered by the pituitary glandwhich secretes a surge of hormonal agents into the blood stream, initiating a chain reaction to occur. The male and female gonads are subsequently activated, which puts them into a state of rapid growth and development; the triggered gonads now commence the mass production of the necessary chemicals. The testes primarily release testosteroneand the ovaries predominantly dispense estrogen. The production of these hormones increases gradually until sexual maturation is met.
Some boys may develop gynecomastia due to an imbalance of sex hormonestissue responsiveness or obesity. The first facial hair to appear tends to grow at the corners of the upper lip, typically between 14 and 17 years of age. This is followed by the appearance of hair on the upper part of the cheeks, and the area under the lower lip. Facial hair is often present in late adolescence, around ages 17 and 18, but may not appear until significantly later.
Early maturing boys are usually taller and stronger than their friends.
Pubescent boys often tend to have a good body image, are more confident, secure, and more independent. However, early puberty is not always positive for boys; early sexual maturation in boys can be accompanied by increased aggressiveness due to the surge of hormones that affect them. Nearly half of all American high school girls' diets are to lose weight.
Girls attain reproductive maturity about four years after the first physical changes of puberty appear. Adolescence is marked in red at top right. Growth spurt The adolescent growth spurt is a rapid increase in the individual's height and weight during puberty resulting from the simultaneous release of growth hormones, thyroid hormonesand androgens. The weight gained during adolescence constitutes nearly half of one's adult body weight. The first places to grow are the extremities—the head, hands and feet—followed by the arms and legs, then the torso and shoulders.
During puberty, bones become harder and more brittle. At the conclusion of puberty, the ends of the long bones close during the process called epiphysis. There can be ethnic differences in these skeletal changes. For example, in the United States of America, bone density increases significantly more among black than white adolescents, which might account for decreased likelihood of black women developing osteoporosis and having fewer bone fractures there.
This process is different for females and males. Before puberty, there are nearly no sex differences in fat and muscle distribution; during puberty, boys grow muscle much faster than girls, although both sexes experience rapid muscle development. In contrast, though both sexes experience an increase in body fat, the increase is much more significant for girls. Frequently, the increase in fat for girls happens in their years just before puberty.
The ratio between muscle and fat among post-pubertal boys is around three to one, while for girls it is about five to four. This may help explain sex differences in athletic performance. These changes lead to increased strength and tolerance for exercise. Sex differences are apparent as males tend to develop "larger hearts and lungs, higher systolic blood pressure, a lower resting heart rate, a greater capacity for carrying oxygen to the blood, a greater power for neutralizing the chemical products of muscular exercise, higher blood hemoglobin and more red blood cells".
For example, girls tend to reduce their physical activity in preadolescence   and may receive inadequate nutrition from diets that often lack important nutrients, such as iron.
The Growing Child: Adolescent (13 to 18 Years)
Reproduction-related changes Primary sex characteristics are those directly related to the sex organs. In males, the first stages of puberty involve growth of the testes and scrotum, followed by growth of the penis. The first ejaculation of seminal fluid generally occurs about one year after the beginning of accelerated penis growth, although this is often determined culturally rather than biologically, since for many boys first ejaculation occurs as a result of masturbation.
Menarchethe beginning of menstruation, is a relatively late development which follows a long series of hormonal changes.
Adolescent Growth Spurt
Changes in secondary sex characteristics include every change that is not directly related to sexual reproduction. In males, these changes involve appearance of pubic, facial, and body hair, deepening of the voice, roughening of the skin around the upper arms and thighs, and increased development of the sweat glands. In females, secondary sex changes involve elevation of the breasts, widening of the hips, development of pubic and underarm hair, widening of the areolae, and elevation of the nipples.
Changes in the brain The human brain is not fully developed by the time a person reaches puberty. Between the ages of 10 and 25, the brain undergoes changes that have important implications for behavior see Cognitive development below. However, the creases in the brain continue to become more complex until the late teens. The biggest changes in the folds of the brain during this time occur in the parts of the cortex that process cognitive and emotional information.
However, this does not mean that the brain loses functionality; rather, it becomes more efficient due to increased myelination insulation of axons and the reduction of unused pathways. The areas of the brain involved in more complex processes lose matter later in development. These include the lateral and prefrontal cortices, among other regions.
During adolescence, myelination and synaptic pruning in the prefrontal cortex increases, improving the efficiency of information processing, and neural connections between the prefrontal cortex and other regions of the brain are strengthened. Specifically, developments in the dorsolateral prefrontal cortex are important for controlling impulses and planning ahead, while development in the ventromedial prefrontal cortex is important for decision making.
Changes in the orbitofrontal cortex are important for evaluating rewards and risks. Three neurotransmitters that play important roles in adolescent brain development are glutamatedopamine and serotonin. Glutamate is an excitatory neurotransmitter. During the synaptic pruning that occurs during adolescence, most of the neural connections that are pruned contain receptors for glutamate or other excitatory neurotransmitters.
Dopamine is associated with pleasure and attuning to the environment during decision-making. During adolescence, dopamine levels in the limbic system increase and input of dopamine to the prefrontal cortex increases. Serotonin is a neuromodulator involved in regulation of mood and behavior. Development in the limbic system plays an important role in determining rewards and punishments and processing emotional experience and social information.