Puberty

Puberty is the time of life in which physical and hormonal changes take place in the body making it capable of reproduction. It occurs primarily during early adolescence. Changes can begin as early as age nine or as late as age seventeen. Nutrition, health, and genetic factors determine when a child starts puberty. Girls usually start puberty earlier than boys. First changes are internal; external changes are noticeable in the development of breasts and appearance of pubic hair. The sequence of changes for girls are as follows:

• Ovaries increase production of estrogen
• Internal sex organs begin to grow larger
• Breast bud stage
• Pubic hair begins to appear
• Weight spurt begins
• Peak height spurt
• Peak muscle and organ growth (also, hips become wider)
• Menarche (first menstruation)
• First ovulation
• Final pubic hair pattern
• Full breast growth

Boys' changes are also initially internal. The first external signs are growth of the scrotum and appearance of pubic hair. The sequence of changes for boys are as follows:

• Testes increase production of testosterone and progesterone
• Testes and scrotum grow larger
• Pubic hair begins to appear
• Penis growth begins
• First ejaculation
• Weight spurt begins
• Peak height spurt
• Peak muscle and organ growth (also, shoulders become broader)
• Voice lowers
• Facial hair appears
• Final pubic hair pattern