Adrenergic nerves are classified into α and β receptors. In α receptors there is high affinity for epinephrine followed by norepinephrine then isoproterenol. In β receptors there is high affinity for isoproterenol then epinephrine to norepinephrine.
Norepinephrine NE neurotransmitters formation start with the uptake of tyrosine into the cytoplasm. Dopamine is transformed into dopa then to dopamine which converted in the storage vesicles into norepinephrine. NE is metabolized in synaptic cleft by COMT
Autonomic nervous system ANS is part of peripheral nervous system. ANS is composed of sympathetic and parasympathetic nervous system. The main neurotransmitter at parasympathetic receptors is acetylcholine, whereas norepinephrine is the main neurotransmit