Question

Which of the following is true about the circulatory system of animals?

• A. Only vertebrates, annelids and cephalopods, have closed circulatory system.
• B. All vertebrates have separate pulmonary and systemic circulations.
• C. The circulatory system of Mammals and Birds are similar to Amphibians.
• D. Animals can have only one heart or else the circulatory system would not work.

Answer 1

The correct option is A

Only vertebrates, annelids and cephalopods, have closed circulatory system.

All vertebrates, annelids like earthworms and cephalopods like octopi, have a closed circulatory system, with the complete separation of both systemic and pulmonary circuits. The rest of the animal world has an open circulatory system. Birds, like mammals, have a 4-chambered heart. Amphibians and reptiles have 3 chambers in their hearts. Animals can have more than one heart. Octopi have 3 hearts, cockroaches have thirteen and some humans can have two hearts and still function. In theory, if we were to have 2 hearts, we could not only survive but thrive by building more strength and endurance.