Question

Is the circulatory system open or closed?

Answer 1

Open circulatory system:

1. The blood or hemolymph is free-flowing in such a system.
2. No blood vessels or cavities are present so the hemolymph directly bathes the organs and tissues.
3. Snails, cockroaches, and spiders have open circulatory systems.

Closed circulatory system:

1. The blood circulates within closed vessels.
2. Blood is not in direct contact with the tissues as it is pumped by the heart and circulated through vessels.
3. Humans, squids, cats, and earthworms have closed circulatory systems.