Puberty in Males: Physical Changes and Development

Boys

* Increased testosterone production. Testosterone is a hormone that is responsible for the development of male secondary sexual characteristics, such as a deeper voice, facial hair, and muscle mass.

* Enlargement of the testes and penis. The testes produce sperm, and the penis is the organ through which sperm is ejaculated.

* Development of the scrotum. The scrotum is a sac of skin that holds the testes.

* Increased production of seminal fluid. Seminal fluid is a fluid that helps to transport sperm.

* Increased sex drive. Testosterone also increases sexual desire.

Girls

* Increased estrogen production. Estrogen is a hormone that is responsible for the development of female secondary sexual characteristics, such as breasts, wider hips, and pubic hair.

* Menstruation. Menstruation is the shedding of the lining of the uterus. It occurs when a woman is not pregnant.

* Ovulation. Ovulation is the release of an egg from the ovary. It occurs about two weeks before a woman's period is due.

* Increased production of cervical mucus. Cervical mucus is a fluid that helps to transport sperm to the uterus.

* Increased sex drive. Estrogen also increases sexual desire.