👶 Growing from Baby to Child

When you were born you were very small. You couldn’t walk or talk or do anything for yourself. Now you are much bigger and can do many things for yourself.

🌱 Changes as You Grow

Throughout your childhood you continue to grow and develop. You not only grow taller and heavier, but your body changes in other ways too. Some of the changes mean that you are becoming an adult and will be able to reproduce. This stage in your life is called puberty.

💡 When Puberty Begins

Puberty starts at different ages in boys and girls. In boys, puberty usually starts when they are about 13 years old. In girls, puberty often happens from the age of 11. The changes that happen during puberty don’t happen all at once, but in stages. These changes are caused by chemicals in your body called hormones.

📏 Growing Fast

The first change you will notice is that you grow very fast. Boys can easily grow about 10 cm in a year. Girls can grow up to 12 cm in a year as puberty starts.

💇‍♂️ Hair and Skin Changes

One of the other changes you will notice is that your body grows more hair. In boys, hair begins to grow on the face, armpits and other parts of the body. In girls, hair begins to grow in the armpits and other parts of the body.

Your skin can also get oily. Many boys and girls get pimples during puberty.

💪 Body Shape and Voice

A boy’s shoulders and chest will get broader as his body muscles develop. His voice will change and become deeper.

A girl’s hips will get wider and she will start to develop breasts. Her voice will also become a little deeper.

🧬 What Happens Inside Your Body

There are also important changes that take place inside the bodies of boys and girls during puberty. These changes happen in the reproductive system and make it possible for a boy to become a father and for a girl to become a mother when they are older.

🌸 The Job of the Reproductive System

The main job of the reproductive system is to make special cells called sex cells that are needed for reproduction. In males, the sex cells are called sperm. In females, the sex cells are called eggs or ova (one egg is called an ovum). During reproduction, a sperm and an egg join together to form a new living being that will grow into a baby. This process is called fertilisation.

💡 How Puberty Triggers Reproduction

A boy’s body starts to make sperm during puberty. In girls, ova start to develop. Menstruation in girls starts about a year after puberty begins. This is when an unfertilised egg is released from the body together with the lining of the uterus, which causes some bleeding. Menstruation happens about once a month but is often not regular until a girl is older.

🧍‍♂️ The Male Reproductive System

The male reproductive organs include two testes, which produce the sperm (one is called a testis), the sperm duct, which carries the sperm to the penis, and the penis, which transfers the sperm into the female’s body.

The diagram shows the parts of the male reproductive system.

👩‍🍼 The Female Reproductive System

The female reproductive organs include the ovaries, which produce the ova or egg cells, the uterus (also called the womb) where the baby develops, the oviducts where fertilisation takes place, and the birth canal, which receives the sperm from the male and through which the baby is born.

The diagram shows the parts of the female reproductive system.