Development In Puberty

Puberty is the stage of adolescence during which girls and boys undergo the physical and hormonal changes that signal their transformation into women and men. Puberty is activated by the hypothalamus and pituitary glands located at the base of the brain; in girls, the hypothalamus causes the pituitary gland to increase its production of estrogen; in boys, the production of testosterone is increased. Puberty typically occurs between the ages of 10 and 16.

Height and Weight Gain

• One of the first signs of puberty onset is a dramatic growth spurt. Boys and girls grow several inches over a short period of time; nearly 20 percent of adult height is achieved during puberty. Girls tend to experience a growth spurt nearly two years before their male counterparts. Girls and boys going through puberty also experience an increase in their body mass as well as a re-distribution of weight. Girls experience an increase in body fat in the upper and lower halves of their body, giving them a curvier appearance. Boys also gain fat, but gain a greater amount of muscle.

Hair Growth

• During puberty, adolescent boys and girls experience new hair growth on specific body parts. Typically, girls aged 9 to 15 will begin to notice a growth of underarm and pubic hair. Initially the hair will be straight and sparse, but through the progression of puberty the hair will become thicker and curly. Pubic hair will begin to take on a triangular shape.

  Boys aged 13 to 15 will also begin to notice underarm, facial and pubic hair. As puberty progresses, male pubic hair will begin to spread toward their thighs. Boys in the latter stages will also grow hair around the anus. By the age of 16 they will have the majority of their adult facial hair.

Breast Development

• Between the ages of 9 and 15, adolescent girls develop breasts. They begin as small "buds"; girls at this stage of growth may begin wearing a training bra. Sensitivity to the area increases and girls may find normal activities, such as sleeping on their stomachs, uncomfortable.

Menstruation Cycle

• Girls typically between the ages of 10 and 15 will begin menstruation. Menstruation is the monthly cycle indicating female fertility, during which a girl bleeds from her uterus through her vagina. Preceding the onset of an adolescent girl's menstrual cycle, she can experience a clear discharge from her vagina; this is simply a process of self-cleaning. Before and during a girl's menstrual period, she may suffer from mood swings, abdominal cramps, back pain and food cravings.

Voice Changes

• Males in the midst of puberty will experience a gradual deepening of their voice. In the beginning of this process, their voices can occasionally become high pitched and "crack."

Penis Development and Nocturnal Emissions

• Between the ages of 12 and 15, a pubescent boy will experience growth in his testicles and scrotum. His penis will lengthen and widen. Some boys experience nocturnal emissions or "wet dreams" during this time. This is when a sexual dream causes the boy's penis to harden and ejaculate in his sleep. Nocturnal emissions are a normal part of puberty that occur as a boy's body acclimates itself to his stirring hormones, developing sexual organs and increased desire for sexual activity.