Coordination and control - The endocrine system - OCR Gateway Hormones and puberty
The endocrine system secretes hormones into the bloodstream from glands throughout the body. Hormones produce an effect on specific target organs in the body.
pubertyTime during which sexual maturity happens. is the stage in life when a child's body develops into an adult's body. The changes take place gradually, usually between the ages of 10 and 16.
Changes occur at puberty because of the hormoneChemical messenger produced in glands and carried by the blood to specific organs in the body.:
testosterone - produced by the testes - controls the development of male secondary sexual characteristics
oestrogen - produced by the ovaries - controls the development of female secondary sexual characteristics
The development of secondary sexual characteristics is shown in the table below.
Boys only
Boys & girls
Girls only
Voice breaks
Pubic hair grows
Voice deepens gradually
Hair grows on face and body
Underarm hair grows
Hips get wider
Body becomes more muscular
Sexual organs grow and develop
Breasts develop
Testes start to produce sperm cells
Ovaries start to release egg cells - menstruation starts
Boys only
Voice breaks
Boys & girls
Pubic hair grows
Girls only
Voice deepens gradually
Boys only
Hair grows on face and body
Boys & girls
Underarm hair grows
Girls only
Hips get wider
Boys only
Body becomes more muscular
Boys & girls
Sexual organs grow and develop
Girls only
Breasts develop
Boys only
Testes start to produce sperm cells
Boys & girls
Girls only
Ovaries start to release egg cells - menstruation starts
You can see that some of the changes in puberty happen to both sexes, whilst others only occur in those born male or female. Both boys and girls will have a growth spurt during which time their height increases more quickly than at any other time in their life. This tends to happen earlier in girls. The graph below shows this.