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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.

Part of Biology (Single Science)Organism level systems

Hormones and puberty

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 :

  • 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 onlyBoys & girlsGirls only
Voice breaksPubic hair growsVoice deepens gradually
Hair grows on face and bodyUnderarm hair growsHips get wider
Body becomes more muscularSexual organs grow and developBreasts develop
Testes start to produce sperm cellsOvaries start to release egg cells - menstruation starts
Boys onlyVoice breaks
Boys & girlsPubic hair grows
Girls onlyVoice deepens gradually
Boys onlyHair grows on face and body
Boys & girlsUnderarm hair grows
Girls onlyHips get wider
Boys onlyBody becomes more muscular
Boys & girlsSexual organs grow and develop
Girls onlyBreasts develop
Boys onlyTestes start to produce sperm cells
Boys & girls
Girls onlyOvaries 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.

A graph to show the different growth rates between boys and girls.
Figure caption,
Boys and girls grow at different rates