Biology / Unit 12 Bio 2929 short lesson, about 20 seconds
One Molecule Can Signal as Both Hormone and Neurotransmitter
Captions available
The idea
What distinguishes a hormone from a neurotransmitter is release site and distance, not identity — a neurotransmitter acts locally at a synapse, a hormone travels through blood to targets.
In practice
Norepinephrine released at a synapse acts within microns; released into blood, the same molecule reaches organs body-wide.
Where people slip
"Hormones and neurotransmitters are entirely different," per Bio 2927, mistakes a role split for chemical split.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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