Da VIP Academy / GED / Science / Life Science
Human Body Systems
Explain how major body systems function and interact.
How it works
Systems work in pairs
The respiratory system brings in oxygen; the circulatory system delivers it. The digestive system breaks food into nutrients; the circulatory system carries them. Questions usually ask how two systems cooperate.
Homeostasis
The body holds internal conditions steady — temperature, blood sugar, water balance. Sweating, shivering, and insulin release are all homeostasis in action.
Worked examples
Why does heart rate rise during exercise?
- Muscles use more oxygen and produce more carbon dioxide.
- Blood must move faster to deliver oxygen and remove waste.
- The circulatory system speeds up to meet respiratory demand.
Words to know
- Homeostasis
- Maintaining stable internal conditions.
Test-day tips
- • When a question names two systems, the answer is almost always about exchange or transport.