The basic building blocks of the body are tiny structures called cells.The human body contains trillions of cells, such as nerve cells, muscle cells, and fat cells. The instructions on how each cell develops and functions are held in coded form by a chemical called deoxyribonucleic acid (DNA), which is found in tiny structures called chromosomes in the nucleus (control centre) of every cell. If a molecule of DNA could be unravelled, it would reveal a structure like a twisted ladder called a double helix.

The human body

Myths, magic, and medicine

Study and dissection

The microscopic body

Looking inside the body

The body's framework

Inside bones

Joints between bones

The body's muscles

The moving body

The nervous system

The brain

Inside the brain

Skin and touch

Eyes and seeing

Ears and hearing

Smell and taste

Chemical messengers

The heart

In circulation

The blood

Breathing to live

Inside the lungs

Eating

Digestion

Waste disposal

Male and female

A new life

Growth and development

Future bodies

Timeline

Find out more

Glossary

Index