Question

Evolution of heart in vertebrates biology discussion

Answer 1

The circulatory system is of two types: open of closed. In open circulatory system, blood pumped by the heart passes through large vessels into open spaces or body cavities called sinuses. This type of system is present in Arthropods and Molluscs.

In closed circulatory system the blood pumped by the heart is always circulated through a closed network of blood vessels. This system is more advantageous as the fluid is regulated in better ways. The closed circulatory system is present in Annelids and Chordates.