Question

What is open circulatory system?

Answer 1

An open circulatory system describes a system where blood and interstitial fluid are allowed to mix in an organism. Interstitial fluid is just the fluid found between cells in the body. An open circulatory system is present in cockroaches.

Organisms that utilize an open circulatory system don't have 'true' blood since it is mixed with other fluids. The 'blood' in these organisms is defined as hemolymph, or the mixture between blood and interstitial fluid. You can remember that because 'heme' is Latin for 'blood,' and 'lymph' refers to liquid.

Humans have a closed circulatory system, which means that our blood and other fluids never mix.