Biology / Unit 13 Bio 3185 short lesson, about 20 seconds
Open versus Closed Circulatory Systems
Captions available
The idea
An open circulatory system releases blood into open body cavities where it bathes tissue directly; a closed system keeps blood confined within vessels throughout its circuit.
In practice
An insect's hemolymph pools around organs; a vertebrate's blood stays inside arteries, veins, and capillaries.
Where people slip
An open system moves blood at lower pressure, limiting how quickly it delivers oxygen to active tissue.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Builds on
- Nothing. This is a starting point.
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