Question

A circulatory system is the main method for transporting gases and nutrients throughout the body. Explain what happens in a closed circulatory system and compare a closed circulatory system to an open closed circulatory system.

a) In a closed circulatory system, blood is pumped through vessels, while in an open circulatory system, blood is not confined to vessels.
b) In a closed circulatory system, blood is not confined to vessels, while in an open circulatory system, blood is pumped through vessels.
c) In both closed and open circulatory systems, blood is pumped through vessels.
d) In both closed and open circulatory systems, blood is not confined to vessels.

Answer 1

A closed circulatory system circulates blood within vessels for efficient transport of substances, whereas an open circulatory system uses a hemocoel with less structure but uses less energy.

Step-by-step explanation:

In a closed circulatory system, blood is pumped by the heart through vessels and is kept separate from the body's interstitial fluid. This system, found in vertebrates and some invertebrates, such as annelid earthworms, is more controlled and structured, allowing efficient transport of nutrients and waste products. By contrast, in an open circulatory system, which is seen in arthropods and most mollusks, the fluid called hemolymph is pumped by the heart into a body cavity known as a hemocoel, and then reenters the heart through openings called ostia. This system is less energy-intensive but is not as efficient at moving blood to metabolically active organs that require high amounts of oxygen.

Therefore, the correct answer to the initial question is (a): In a closed circulatory system, blood is pumped through vessels, while in an open circulatory system, blood is not confined to vessels.