The Human Brain
A 1-hour guided curriculum · Age 10 · Beginner Friendly
Inside your skull sits about 1.4 kilograms of pinkish-grey tissue with roughly the wobble of firm jelly — and it never switches off. Right now it is reading these words, keeping your heart beating, holding you upright in your chair, remembering what you had for breakfast, and deciding whether to keep reading. All at the same time. Your brain is the control centre for everything you think, feel, sense and do, and it manages the whole job on about 20 watts of power — less than the bulb in your bedside lamp.
Your brain isn't one blob doing one job — it's a team, and every player has a position. The cerebrum is the big wrinkly part on top that thinks, talks, imagines and solves problems. The cerebellum ("little brain") sits at the back and makes your movements smooth and balanced — it's why you can ride a bike without falling off. The brain stem at the bottom runs everything you never have to think about: breathing, heartbeat, swallowing. Deep inside, the hippocampus is your save button for new memories, and the amygdala is the alarm bell that rings when something is scary or exciting.
Your brain is built from about 86 billion neurons — messenger cells shaped a bit like trees. Bushy dendrites catch incoming messages, the cell body decides whether the message is worth passing on, and a long cable called the axon carries the signal onward as a tiny pulse of electricity. But here's the strange part: neurons never actually touch. At the end of the axon there's a microscopic gap called a synapse, and the electrical signal can't jump it. Instead the neuron squirts out chemical messengers called neurotransmitters, which float across and land on the next cell — turning the message back into electricity on the other side. Electric, then chemical, then electric again, billions of times every second.
A message is about to travel from one neuron to the next. Click the six steps in the right order.
Every time you learn something, your brain physically changes shape. Neurons that fire together grow stronger connections — scientists call this neuroplasticity, and it is the real reason practice works. Your hippocampus decides which of the day's events are worth keeping and files them away, mostly while you sleep. Meanwhile your brain is making decisions faster than you can notice: light hits your eye, travels to the back of your brain, gets recognised, and an order goes out to your hand — the whole loop takes about a quarter of a second. Time yourself below and see.
Numbers will flash on screen. Type them back in the same order. Each time you get it right the list grows by one digit. Most adults top out around seven — that is the size of your short-term memory.
Click the button that matches the colour of the ink, not the word itself. Round 1 is easy. Round 2 is where your brain starts arguing with itself.
Your brain is not sealed off in your head — it is wired into every last corner of you. The spinal cord runs down your back like a data cable, and nerves branch off it to reach your fingertips and toes. Your five senses stream information in; your muscles take orders back out. And because the brain is a living organ, you can look after it. Exercise pushes more oxygen-rich blood into it and helps grow new connections. Sleep is when the hippocampus files the day's memories properly — skip it and you literally learn less. Water and good food matter too: your brain is about 75% water and burns roughly a fifth of all the energy you eat.