<Tr> <Th> Synonyms </Th> <Td> <Ul> <Li> NE, NA, </Li> <Li> Noradrenaline, </Li> <Li> (R) - (--) - Norepinephrine, </Li> <Li> l - 1 - (3, 4 - Dihydroxyphenyl) - 2 - aminoethanol </Li> </Ul> </Td> </Tr> <Ul> <Li> NE, NA, </Li> <Li> Noradrenaline, </Li> <Li> (R) - (--) - Norepinephrine, </Li> <Li> l - 1 - (3, 4 - Dihydroxyphenyl) - 2 - aminoethanol </Li> </Ul> <Li> NE, NA, </Li> <Li> (R) - (--) - Norepinephrine, </Li>

What role does the neurotransmitter norepinephrine have in the cardiac system