Circulatory and Respiratory Systems

A series of free Science Lessons for 7th Grade and 8th Grade, KS3 and Checkpoint Science in preparation for GCSE and IGCSE Science.

Circulatory System
The heart keeps all the blood in the circulatory system flowing. Blood helps oxygen get around your body. As the heart beats, it pushes blood into the arteries and draws blood in from the veins. The beating of the heart makes the blood circulate around the body.

The heart and blood vessels make up the circulatory system. The beating of the heart can be checked by taking the pulse.

Breathing and Respiration
The act of breathing is part of the respiratory system. It is a process where air travels into and out of the lungs.

Respiration is a chemical reaction that happens in all living cells, including plant cells and animal cells. It is the way that energy is released from glucose so that all the other chemical processes needed for life can happen. Do not confuse respiration with breathing.

Respiratory System
When you breathe, you transport oxygen to the body’s cells to keep them working, while also clearing your system of the carbon dioxide that this work generates. How do we accomplish this crucial and complex task without even thinking about it? Investigate how lungs help keep us alive.

Try the free Mathway calculator and problem solver below to practice various math topics. Try the given examples, or type in your own problem and check your answer with the step-by-step explanations.

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