<Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (August 2012) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (August 2012) (Learn how and when to remove this template message) </Td> </Tr> <Table> <Tr> <Th_colspan="2"> Cardiac Cycle / Heartbeat </Th> </Tr> <Tr> <Td_colspan="2"> </Td> </Tr> <Tr> <Th> Organisms </Th> <Td> Animalia * </Td> </Tr> <Tr> <Th> Biological system </Th> <Td> Circulatory system </Td> </Tr> <Tr> <Th> Health </Th> <Td> Beneficial </Td> </Tr> <Tr> <Th> Action </Th> <Td> Involuntary </Td> </Tr> <Tr> <Th> Method </Th> <Td> Blood is allowed to enter relaxed ventricle chamber from vein through venous valve . Heart muscle contracts ventricle chamber and blood is expelled through arterial valve to artery . </Td> </Tr> <Tr> <Th> Outcome </Th> <Td> circulation of blood </Td> </Tr> <Tr> <Th> Frequency </Th> <Td> 60--100 per minute (Humans) </Td> </Tr> <Tr> <Th> Duration </Th> <Td> 0.6--1 second (Humans) </Td> </Tr> <Tr> <Td_colspan="2"> Animalia with the exception of Porifera, Cnidaria, Ctenophora, Platyhelminthes, Bryozoan, Amphioxus . </Td> </Tr> </Table> <Tr> <Th_colspan="2"> Cardiac Cycle / Heartbeat </Th> </Tr>

Name and explain the different stages of the cardiac cycle