Puberty.
Puberty. Dr. Sayeed Ahmad D. I. Hom. (London) Puberty is the most obvious sign that an individual has entered adolescence. Technically, puberty refers to the period during which the individual becomes capable of sexual reproduction. More broadly, however, puberty is used as a collective term for all the physical changes that occur in a growing girl or boy as the individual passes from childhood to adulthood. The physical changes of adolescence are triggered by hormones (chemical substances in the body) that act on specific organs and tissues. In boys, a major change is increased production of the hormone testosterone, while girls experience increased production of the hormones called estrogens. In both sexes, a rise in growth hormone produces a growth spurt. During this spurt, which lasts two or more years, an individual commonly grows 2 to 4 inches (5 to 10 centimeters) taller per year. Sexual development. Many of the most dramatic changes of puberty involve sexual development. Intern...