Dr. S. YAMUNA
Adolescence can be a dicey period of drastic physical changes. This column helps young adults negotiate these changes.
EIGHTEEN-YEAR-OLD Amit (not real name), swimmer, has been hesitant to go swimming these days. When asked, he says that he is not comfortable taking off his garments in the pool. He feels that his chest does not have adequate hair and that he is not muscular. He has been going to the gym for the last six months. After a thorough physical examination, he was found to be having normal external development.
Puberty is marked by a series of changes which take place in a growing child over a period of three to five years that enable an individual to procreate. Puberty in boys begins between ten and a half years and 12 years. Different boys have different rates of growth and development during this period. The pubertal changes in boys begin two years later than the girls and continue well beyond the teenage period.
The first visible change is the increase in the size of the testis. Then the penis grows in size. The scrotal skin changes in colour and the scrotal sac enlarges to accommodate the enlarging testes. The testes secrete the hormone testosterone that brings about the secondary sexual characteristics like facial hair, chest hair and breaking of voice.
The next perceptible change is the gain in height. Till the onset of puberty, a boy grows approximately three to five centimetres per year. During the peak height gain, boys gain up to nine to 10 cm per year. The ultimate height depends on parental height, nutrition, physical factors like absence of chronic illness and emotional factors like secure family environment.
The hands and feet become bigger. The length of the upper limbs and lower limbs increase. Facial bones expand. The angle of the jaw becomes sharp. The voice box enlarges with breaking of the voice. Eyeballs enlarge. Refractory errors, especially short sightedness come to attention during this period.
Muscle bulk increases along with the growth in height. Muscle power increases at the end of muscle growth. Fat deposition decreases and thus towards the end of puberty, boys appear more muscular and sturdy. Until the completion of linear growth, only aerobic exercises are advised. Exercises like weight lifting to augment muscle bulk should be avoided. Such exercises can reduce the rate of height gain per year.
Hair growth on the face begins around 14 to 16 years, first over the lips. The central part fills next, followed by growth on the chin and then the cheeks. Frequent shaving would not augment or alter the order in which the hair appears.
As puberty progresses, the boy gets the full quota of pubic hair around the genitals, in stages. Chest hair is the last to appear. The amount of chest hair depends on hereditary factors.
Along with the increase in the size of the testes, the prostate enlarges and also starts secreting prostatic juices. The testes produce sperms around the same time. The semen gets expelled while handling the genitals or during dreams. This is called nocturnal emission.
The male hormones increase the sweat glands in the axilla and other parts of the body. The fat glands on the face, upper chest and upper back increase in numbers. When these fat glands get blocked and infected, pimple or acne appears.
Sometimes, the breasts grow for a short period of up to a year and a half in boys too. But this is transient. With the increase in the muscle mass, the fat deposition decreases and the size of the breasts regresses. Boys lose their chubbiness during puberty.
So, here Amit was growing normally. But his puberty is still not complete. He is in the late stages of puberty during which the muscle bulk is increasing gradually. His chest hair has just started to grow.
Some boys have an early onset of puberty. They are early bloomers. As they complete the pubertal changes earlier, they may look muscular, powerful and hairy. But as these boys have fewer years of growth, their final height remains lower in comparison to late bloomers. The early bloomers do well in contact sports like football.
In early adolescence, the boys are concerned about the bodily changes and get worried at the delay in comparison to their peers. During middle adolescence, they accept the changes but are concerned about the adequacy. During late adolescence, they complete the growth and begin to focus on their future goals.
S. Yamuna is a consultant paediatrician and adolescent physician based in Chennai.
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