Why is the human circulation em called a double circulation system?
In the double circulation system there are two routes that the blood can take:
1. Through the lungs
2. To the rest of the body
The blood starting in the heart has no oxygen in it. It flows from the heart and goes through the lungs, this is where it picks up the oxygen. The blood returns to the heart where it is redirected to go on the second route. This oxygenated blood is now delivered around the rest of the body via arteries, once the oxygen has been dropped off at the muscles (which need it for respiration) it returns to the heart deoxygenated via the veins.
Then the cycle repeats itself.
EL
Related Biology GCSE answers
All answers ▸Why/how do plants both respire and photosynthesise?
What are the comon features of an animal cell and what are there functions?
A student cut a piece of potato into 10 discs, each 1mm thick and with a 10mm diameter. He then placed them in a beaker of deionised water. After a couple of days, they had increased in size- both thickness and diameter. Explain why this is the case.
Why do we use aseptic techniques in laboratories?