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An Introduction to Sexual Development
Sexual Development by Age Groups
Male Sexual Development
Female Sexual Development
Children and Sexuality
Adolescent sexuality
References
SEXUAL DEVELOPMENT
MALE
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Extra production of testosterone in the testes triggers puberty in boys. Each boy is unique in the timing of each phase of development, and much depends on hereditary factors, diet and climate. Boys usually experience puberty between the ages of 9 and 14. There is an initial growth spurt at around 13, when the nose, arms, legs and penis grow, but the body's main growth starts about a year later, so they look lanky and awkward for a while. Most boys reach their full height by 18, but bone density and muscle mass continue to increase for several more years. Testosterone increases the ratio of lean muscle to body fat, and causes the skin to become oilier, which can lead to acne. Some boys develop puppy-fat 'breasts' during puberty, but these only last for a few months until hormone levels settle down.
Hair and voice: pubic hair first appears between ages 12-16, at the base of the penis and then spreads towards the tummy and thighs. Underarm hair and coarser body hair start growing later. The voice becomes deeper gradually - or 'breaks' suddenly - and the Adam's apple develops. Facial hair and the voice breaking are often the last signs of sexual maturity to become evident.
Genitals: the penis grows longer and wider. The testes increase in size, and production of sperm and seminal fluid starts. Erections become much more frequent than very early in puberty, often without any sexual stimulus and at often at awkward moments. The first ejaculation occurs about a year after puberty begins, usually from 13-17. It indicates that a boy is producing sperm and may be capable of reproduction. Nocturnal emissions - 'wet dreams' - are a common experience for teenage boys as the semen that is formed spills over during sleep- sometimes associated with erotic dreams. Once a boy starts to masturbate or become sexually active, ‘wet dreams’ become less frequent. Most males reach the height of their sexual responsiveness in their late teens.
