Question 23

Outline the production, release, and fate of noradrenaline at the sympathetic nerve terminal. 

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College Answer

The question consisted of three parts (production, release and fate of noradrenaline). The 
context was the sympathetic nerve terminal. The synthesis of Noradrenaline from Tyrosine was 
expected. Better answers mentioned the roles of Tyrosine Hydrolase, DOPA Decarboxylase and 
DOPA Beta-hydroxylase. Candidates were expected to describe the storage of Noradrenaline in 
vesicles and Ca++-mediated exocytosis in response to an action potential. Noradrenaline binds to 
post-synaptic and pre-synaptic receptors. Re-uptake, metabolism by MAO and COMT, and 
diffusion away from the synaptic cleft should have been discussed. An accurate diagram could 
be used to enhance the answer.