Henry is a 12-year-old who has just entered junior high school. Henry has noticed that his body is going through some physical changes. As a result, he has become self-conscious about his physical appearance. He has also begun taking measures to insure more privacy at his home. For example, he locks the door every time he enters the bathroom, and he always takes his phone calls in his room with his door closed. Henry also values his relationships with his friends and has begun spending more time with them. Henry's behaviors and physical changes are common during adolescence.
Adolescence refers to the period of human growth that occurs between childhood and adulthood. Adolescence begins at around age 10 and ends around age 21. Adolescence can be broken into three stages: early adolescence, middle adolescence, and late adolescence. Each stage has its own characteristics. Let's take a look at each stage in more detail below.
Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction. It is initiated by hormonal signals from the brainto the gonads: the ovaries in a girl, the testesin a boy. In response to the signals, the gonads produce hormones that stimulate libido and the growth, function, and transformation of the brain, bones, muscle, blood, skin, hair, breasts, and sex organs. Physical growth—height and weight—accelerates in the first half of puberty and is completed when an adult body has been developed. Until the maturation of their reproductive capabilities, the pre-pubertal physical differences between boys and girls are the external sex organs.