Puberty is the process of physical changes by which a child's body becomes an adult body capable of reproduction, it is the time at which a growing boy or girl begins the process of sexual maturation. At puberty, a young man's body begins making sperm and he starts to be able to ejaculate, which is Semen coming out from his penis when he is sexually excited. If he has sexual intercourse (sex) with a young woman, he can make her pregnant. In a strict sense, the term puberty (derived from the Latin word puberatum (age of maturity, manhood)) refers to the bodily changes of sexual maturation rather than the psychosocial and cultural aspects of adolescent development. Adolescence is the period of psychological and social transition between childhood and adulthood. Adolescence largely overlaps the period of puberty, but its boundaries are less precisely defined and it refers as much to the psychosocial and cultural characteristics of development during the teen years as to the physical changes of puberty. Puberty involves a series of physical stages or steps that lead to the achievement of fertility and the development of secondary sex characteristics, the physical features associated with adult males and females (such as the growth of pubic hair). While puberty involves a series of biological, or physical, transformations, the process can also have an effect on the psychosocial and emotional development of the adolescent. Puberty is initiated by hormone (which are chemicals) signals from the brain to the gonads (the ovaries and testes). In response, the gonads produce a variety of hormones that stimulate the growth, function, or transformation of brain, bones, muscle, blood, skin, hair, breasts, and sex organs. Growth accelerates in the first half of puberty and stops at the completion of puberty. Before puberty, body differences between boys and girls are almost entirely restricted to the genitalia. During puberty, major differences of size, shape, composition, and function develop in many body structures and systems. The most obvious of these are referred to as secondary sexual characteristics. People all over the world start puberty at different ages. Changes that happen to young men and women during puberty include the sex organs growing bigger, hair appearing on the body, and growing taller and stronger. People often notice young men's voices getting deeper, and young women growing breasts and starting to menstruate (have periods). Puberty causes:
Physical changes, such as rapid growth spurts, the development of breasts in girls and an increase in penis size in boys Psychological changes that can cause teenagers to become moody, self-conscious and aggressive Behavioural changes that can cause some teenagers to experiment with new and potentially risky activities, such as smoking, drinking, alcohol and sex. Because puberty is the time in a child's life when he or she becomes able to make children, this is seen as very important. Therefore, people in many countries around the world have different ways of marking this event. 1.2 DEFINITION OF PUBERTY
Puberty is the period or age at which a person is first capable of sexual reproduction of offspring: in common law, presumed to be 14 years in the male and 12 years in the female. 1.3 ONSET OF PUBERTY
On average, girls start puberty between the ages of 9 and 14 years, and boys start between 10 and 17 years. However, just because a person's puberty does not start during these ages does not mean they are not normal. [William and Tanner (1986)] People from all over the world start puberty at different ages. This is because of their environment (things around them), and maybe even events in their lives. [Giannini and Slaby, 1981. ] The timing of the onset of puberty is not completely understood and is likely determined by a number of factors. One theory proposes that reaching a critical weight or body composition may play a role in the onset of...