Why do humans have a double circulatory system?

Ask the student: what other option is there? What are the differences between the two? 

Answer: Humans have a small surface area to volume ratio, so diffusion alone is not enough to meet the high metabolic demands. Thus a double circulatory system is needed to provide oxygen and nutrients to all cells in the body.

DV

Related Biology A Level answers

All answers ▸

Please explain the pathway of blood in the mammalian heart.


How can high absorption of salt fro the diet leading to high salt concentration in local capillaries lead to build-up of tissue fluid?


What are some key components within the cell surface membrane, and what are their functions?


what is water potential?