Stage 2: Body Systems and How They Work
Heart, lungs, brain, gut and more — how each body system works.
The Cardiovascular System
The heart, blood vessels and circulation — how blood reaches every cell.
Blood and the Lymphatic System
Blood composition, lymphatics, and how the body transports fluid and immune cells.
The Respiratory System
Lungs, airways and breathing — how oxygen gets in and carbon dioxide gets out.
The Nervous System
Brain, spinal cord and nerves — how the body senses and responds to the world.
The Endocrine System
Hormones, glands and metabolism — the body's chemical signalling network.
The Musculoskeletal System
Skin, bones, joints and muscles — how the body moves and protects itself.
The Immune System
How the body defends itself against infection, cancer and foreign substances.
The Digestive System
From mouth to gut — how food is broken down, absorbed and waste removed.
The Renal System
Kidneys, fluid balance and waste — how the body filters the blood.
The Reproductive System
Male and female reproductive systems, hormones, fertility and pregnancy basics.
Eyes, Ears and Sensory Systems
How we see, hear and sense the world — and what can go wrong.
How Body Systems Work Together
Why no body system works alone, and how the systems interact in real life.