Extras
Freya's bones in her racket arm have become thicker to cope with her intense workouts.
As Lew pushes himself, his body demands more oxygen to keep it going.
From an early age, we learn how to control the movements of our bodies.
We learn to work together by reading the emotions and facial expressions of others.
Danny demonstrates how new motor skills must be learned and developed with practice.
Learn how humans grow from a single cell to beings of more than 37 trillion cells.
See how experience teaches the brain and body to work together and develop new skills.
What determines when we start puberty has until recently been a mystery.
Latest Episodes
Learn how humans grow from a single cell to beings of more than 37 trillion cells.
See how experience teaches the brain and body to work together and develop new skills.