How the Human Body Works
Discover how your body coordinates movement, fuels your cells, and keeps you alive. Learn the mechanics behind everyday sensations from your heartbeat to muscle fatigue.
Like Duolingo, but for How the Human Body Works. Tomo turns the whole topic into a game you play five minutes a day, until it actually sticks.
27 levels across 4 sections, about 54 minutes end to end, roughly 11 days at five minutes a day. It moves through Daily Balance and Vital Signals; The Mechanical Frame: Bones and Muscles; Internal Transport and Processing; and Control, Communication, and Defense. It starts from scratch.
Free forever · No credit card · iPhone & Android
Key ideas in How the Human Body Works
- Homeostasis is a dynamic, active balancing act, not a rigid freeze
- Internal conditions constantly fluctuate around a target baseline as the body counters outside disruptions
- Standing up forces the heart to work harder against gravity to pump oxygen-rich blood up to the brain
- Resting pulse speeds up or slows down automatically to match immediate shifts in oxygen demand
- The brain's internal thermostat monitors blood temperature and triggers opposing physical reactions
- Evaporation of sweat sheds excess heat when the body runs hot
- Involuntary muscle shivering produces heat when core temperature drops
- Breathing rate is primarily triggered by sensors detecting rising carbon dioxide levels in the blood
- The burning urge to breathe comes from carbon dioxide accumulation rather than running out of oxygen
- Pain and fatigue are warning systems designed to force behavior shifts before permanent injury occurs
- Fatigue acts as a protective brake to prevent muscle exhaustion and structural damage
- Pain prompts immediate protective reflexes and protects healing tissues
- The diaphragm contracts downward, flattening out toward the belly
- Expanding the chest cavity drops internal air pressure below outside air pressure
- Air naturally rushes inward to equalize the lower pressure inside the chest
- Lungs are divided into hundreds of millions of tiny air sacs called alveoli
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 the Human 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.
Throughout a normal day, what do your body's vitals usually do?
Get it right to open this lesson and 26 more in the app.
Where How the Human Body Works takes you
- 1
Daily Balance and Vital Signals
- Tuning into Your Body's Baseline
- The Oxygen and Airway Engine
- 2
The Mechanical Frame: Bones and Muscles
- Living Bone and Joint Architecture
- How Muscles Contract and Generate Force
- 3
Internal Transport and Processing
- The Circulatory Plumbing System
- Digestion and Energy Extraction
- Fluid Filtration and Waste Disposal
- 4
Control, Communication, and Defense
- Wiring and Reflexes in the Nervous System
- Chemical Messengers and Immune Defense
4 sections · 9 units · 27 levels. Built to play, not to enroll.
You pick the voice
How the Human 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 the Human Body Works today.
Download Tomo, search How the Human Body Works, and play your first lesson in under a minute.