© Oxford University Press 2008

2.6 Coming full circle

Changes during puberty

Boys

Penis develops

Voice deepens

Facial hair grows

Sperm production starts

Both

Hair grows on sex organs

Spots appear

Notice the opposite sex more

Armpit hair grows

Growth spurt

Hair grows on legs

Girls

Breasts develop

Periods start

Hips widen

© Oxford University Press 2008

The menstrual cycle

One of the changes that happens to girls during puberty is that their periods start.

This is called the ‘menstrual cycle’ because it follows a pattern that repeats every 28 days.

It happens because a girl’s body is preparing itself to receive a fertilised egg.

2.6 Coming full circle

© Oxford University Press 2008

The menstrual cycle

2.6 Coming full circle