Primary Sexual Characteristics - those directly related to reproduction.

Secondary Sexual Characteristics - those that distinguish men from women.

Age 12

larger muscles than boys, breast development,

taller than boys, maturation of labia, clitoris, & uterus,

menarche

Occurs age 14 (2 years after girls)

Longer legs and trunk,

wider shoulders, voice deepens, facial hair, penis grows

The hypothalamus - stimulates the release of hormones/stimulates the pituitary gland,

Pituitary gland - releases luteinizing hormone and FSH (gonadotropins),

gonads release testosterone and estrogen

Decreasing age of onset from 17 in late 1800's to 11.75 now.

Caused by lack or exercise, fat in diet, or hormones in food?

No signs by age 13, can be hereditary,

lack of breast development,

more than five years between breast development and menarche,

lack of pubic hair by age 14, no menarche by age 16

Lack of testicular enlargement by age 14,

Lack of pubic hair by age 15,

More than five years to complete genital enlargement

Signs of puberty before age 7 or 8 including:

breast development, pubic or underarm hair growth, growth spurt, menarche, acne, body odor.

Onset of puberty before age 9 indicated by:

pubic, underarm, or facial hair development,

growth spurt, voice deepening,

acne, body odor.