How Your Body Works
Ever wonder what's happening inside you right now? Discover how your heart pumps, how you breathe, and how your brain controls everything you do in this simple guide to the human body.
Like Duolingo, but for How Your Body Works. Tomo turns the whole topic into a game you play five minutes a day, until it actually sticks.
54 levels across 4 sections, about 108 minutes end to end, roughly 22 days at five minutes a day. It moves through The Power of Your Heart and Lungs, Fueling Your Body, The Control Center, and Moving and Protecting. It starts from scratch.
Free forever · No credit card · iPhone & Android

Key ideas in How Your Body Works
- Valves open and close in response to pressure
- The heart is a double pump with two separate circuits
- Valves act as one-way gates between chambers
- The right side handles deoxygenated blood and the left handles oxygenated blood
- Muscles require more oxygen and energy during exercise
- Atria receive blood and ventricles pump it out
- How the heart prevents backflow of blood
- Increased heart rate speeds up the delivery of blood to tissues
- Blood flows from the right side to the lungs before returning to the left side
- The distinct roles of the two sides of the heart (double pump)
- The relationship between physical activity and heart rate
- The sequence of blood flow through the heart chambers
- Ventricles pump blood out of the heart to the lungs or body
- Thicker muscle walls generate the higher pressure needed for long-distance transport
- The structural difference between atria and ventricles
- Contraction of the diaphragm expands the chest cavity
You've tried the other tabs
Thirty open tabs. Four facts you actually kept.
You watched. You nodded. By Sunday it was gone.
One answer, then back to scrolling.
Eight weeks. You meant to finish. You didn't.
Tomo gives How Your Body Works the Duolingo treatment: levels, streaks, and quick quizzes that test what you just learned. That game loop is what the tabs above never had, so it's the one you actually finish.
Here's what playing it feels like
A real question from this course. Take your best guess.
Since your heart has two separate sides working at once, where does the blood go on its shorter trip?
Get it right to open this lesson and 53 more in the app.
Where How Your Body Works takes you
- 1
The Power of Your Heart and Lungs
- How Your Heart Pumps Blood
- Taking a Deep Breath
- Where Your Blood Goes
- Why We Need Oxygen
- 2
Fueling Your Body
- What Happens to Your Food
- How Your Stomach Works
- Getting Energy from Meals
- Getting Rid of Waste
- The Role of Your Liver
- Why Drinking Water Matters
- 3
The Control Center
- How Your Brain Thinks
- Sending Messages Through Nerves
- How You See and Hear
- 4
Moving and Protecting
- The Strength of Your Bones
- How Muscles Pull and Push
- Your Skin: The Body's Shield
- Fighting Off Germs
- How Your Body Heals
4 sections · 18 units · 54 levels. Built to play, not to enroll.
Tomo is in ChatGPT
Tomo is also a ChatGPT plugin: the same playable courses, built and played inside your chat.
Add Tomo to ChatGPT- What to ask
- “Make me a Tomo course on black holes.” “Turn this chat into a Tomo course.”
- What you get
- Quick questions with instant feedback, hearts and stars, ready to play in about a minute.
- Where it goes
- No sign-up to start. Connect your Tomo account and your streak carries on in the app.
You pick the voice
How Your Body Works is taught in the Explain Like I'm 5 style: no big words. promise.. Want a different feel? In the app you can spin up the same topic in any of Tomo's teaching styles. Same facts, totally different vibe.
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Start How Your Body Works today.
Download Tomo, search How Your Body Works, and play your first lesson in under a minute.