Brain & senses

What is inside

• The brain. A folded lump of about 1.4 kg that thinks, feels, remembers and runs your whole body — in its hard skull, like a walnut in its shell.
• Neurons and signals. A nerve cell: little branches to receive a message, a long wire to carry it, and a tiny gap where it jumps to the next cell.
• The eye. A ball about 2.3 cm across. Light comes in through the pupil, the lens bends it, and an upside-down picture lands on the retina at the back.
• The ear. Sound is air wobbling. The ear catches the wobble, makes it bigger with three tiny bones, and turns it into signals in a snail-shaped tube.
• Reflexes and the spinal cord. Touch something hot and your hand jerks away before your brain even knows — the spinal cord answers on its own.
• Sleep, memory and learning. Every time you practise, the connections between neurons get stronger. While you sleep, the brain replays the day and saves what matters.

Stories in this thing

• What happens when you catch a ball. Eyes, brain, balance and muscles — in half a second
• A message along a nerve. One neuron, one pulse, one tiny gap
• How you see this screen. Light in, picture upside down, brain flips it
• How you hear your name. Air wobbles, a drum shakes, a snail shell listens
• Hand on a hot cup. Why your hand moves before you say ouch
• Why sleep helps you remember. Practice makes paths, sleep saves them

School topics it covers

• Brain & nerves
• Eye & ear
• Reflexes

How children use it

Pull it apart with one slider, tap any part to hear what it does, follow a short story read aloud, then answer a few questions. Every thing comes with experiments to try at home and study notes linked to the NCERT chapter it supports.

More things to open

• Human body — 12 systems, 700+ parts — grow from baby to grandparent.
• Living cell — The tiny factory you are made of — 30 trillion times over.
• Mango tree — Roots, pipes and leaves that cook food from sunlight.
• Solar system — Why it is night, why summer is hot, and how Chandrayaan reached the Moon.
• Satellite — Why it never falls down, and how TV comes from space.
• Family car — Follow one drop of petrol from the tank all the way to the wheels.