peristaltic heart

A peristaltic heart is a simple type of circulatory pump found in many invertebrates. It functions as a blood vessel that contracts rhythmically, pushing the enclosed blood in one direction. This wave of muscular contraction is known as peristalsis. Valves may or may not be present to prevent backflow. This basic mechanism is found in various invertebrates, and some individuals may have multiple pulsating vessels. In some cases, like tunicates, these hearts can even reverse their direction of pumping after a pause. This contrasts with the more complex, chambered hearts found in vertebrates and some invertebrates like cephalopods.12