Builds on
Anatomy of the human bodyOnce you know where each organ sits, you can follow how they pass work to each other.
Body systems and how they connect
No organ works alone — so how does a mouthful of roti reach your toes as energy?
Digestive, circulatory, respiratory, nervous, muscular, skeletal and excretory systems, and the handovers between them that keep you alive every second.
5 depths≈ 210 min of reading79 practice questions
The ladder
Choose how deep to go
Every depth is open. Start where it feels interesting — you can always move back.
- Discoverabout 35 minSeven teams, one bodyMeet the organ systems one at a time — digestive, respiratory, circulatory, excretory, nervous, muscular and skeletal — then follow a roti and a breath across the hand-over points where each system passes its work to the next.Owner-accepted · not line-by-line reviewed
- Understandabout 45 minHow the systems work, and how they hand overGo inside each system: enzymes and the chemical works, the pressure trick that moves air, two circuits through a four-chambered heart, filter-and-reclaim kidneys, the reflex arc and the nerve-to-muscle gap — then follow a breath all the way to a working cell.Owner-accepted · not line-by-line reviewed
- Investigateabout 40 minPredict it, then test itTurn the claims from earlier layers into experiments you can actually run: a ruler-drop reaction test, an iodine test for digested starch, pulse and breathing data before and after exercise, and a look at why a fever is a controlled response rather than a failure.Owner-accepted · not line-by-line reviewed
- Go deeperabout 45 minWhere the tidy rule bendsQuantify why hand-over barriers must be thin, meet the lymphatic system that returns leaked fluid and carries digested fat, see bone as a blood factory and calcium bank, and look at clotting and the blood-brain barrier as hand-overs the body deliberately controls or resists.Owner-accepted · not line-by-line reviewed
- Extendabout 45 minHistory, machines and weightlessnessMeet the arithmetic that proved blood circulates, the instruments that let doctors listen to and image a living body without cutting it, machines that rebuild a failed hand-over, what microgravity does to every system at once, and a few careers and open questions this topic leads to.Owner-accepted · not line-by-line reviewed
Practise and apply
Question bank · 79 questions
9 sections from Foundation to Challenge, each with hints and a worked solution — or play a 10-question round for points and stars.
Foundation 22Core 25Stretch 19Challenge 13
The web
Connected ideas
Follow a connection when you’re curious — some lead into completely different areas.
Body systems and how they connect
Related toanother area
GravityBones, muscles and blood pressure are all built for a life spent pulling against Earth's gravity — which is why astronauts weaken in orbit.
Used inanother area
Data handlingPulse and breathing rate before and after exercise are real class data to average, compare and graph.
Words to know
52 words are explained in these lessons
CellTissueOrganOrgan systemEnzymePeristalsisVilliAlveoliDiaphragmCapillaryReflexExcretion+40 more