Physical changes in adolescence

1. Increase in height

If you have a son or a daughter, you will quickly notice how they progressively increase in size; This is one of the most common changes during puberty. The peak in the girls is between 12-13 years old and in the boys between 14-15 years old. The earlier the age of onset of puberty, the greater the increase in height.

Growth occurs in phases: initially the lower extremities grow and then the trunk, arms and head. This can lead to a feeling of disproportion that translates into insecurity in the adolescent.

When the epiphyses of the bones are closed by hormonal action, the end of growth is marked, giving rise to the definitive size. The final height is reached between 16-17 years in girls and can be delayed until 21 years in boys.

2. Body changes and organ development

There is a enlarged organs (heart, lungs, spleen, kidneys ...) but in addition, there is an increase in muscle mass and bone density and body fat is redistributed:

• To the girls the pelvis and accumulate more fat that the boys. In adulthood, women have a% fat that is between 18-22%
• To the boys the shoulders and they experience increased bone and muscle growth than girls. In adulthood, men have a% fat that is between 12-16%.

3. Increase in bone mass (mo)

Each individual has a genetic potential for OM development, which is only fully achieved if environmental factors such as physical activity and nutrition with calcium intake are optimal.

4. Sexual maturation

The most striking changes take place in and culminate in the acquisition of fertility. The sexual maturation index is medically evaluated by means of the so-called “Tanner Stadiums”And is based on the description of the development of sexual organs and secondary sexual characteristics (markers of femininity and masculinity).

5. Hormones and physical changes in adolescence

Female hormones

The secretion of hormones FSH and LH stimulate the maturation of the ovaries and they activate them to produce other hormones: estrogens and progesterone. With all these, ovulation and the menstrual cycle are induced.

• estrogens, like estradiol, stimulate the development of the breast, the external genitalia, and the uterus.
• Progesterone has a role in the maturation of the endometrium and the breasts.
• There is also an increase in testosterone that stimulates growth, as well as the development of pubic and armpit hair.

The menarche () usually presents about two years after the thelarchy (appearance of breast button). The best reference about its onset is the age of menarche in the mother and the sisters. Height gain after menarche is variable, averaging 7 cm. The breasts and the external and internal sexual organs grow and pubic and armpit hair develops, voice changes, and body odor increases.

Male hormones

A volume of 4 ml of the testes marks the onset of puberty. It usually happens about two years later than in girls and therefore they can appear more physically mature at the same age.

• In the boys the FSH hormone secretion stimulates the formation of sperm.
• The LH hormone stimulates the cells of the testicle to form testosterone and this accelerates the growth of the child, matures the genitals (penis, scrotum and prostate), stimulates the growth of pubic, facial and armpit hair, changes the voice and increases libido.