Biology / Unit 12 Bio 2857 short lesson, about 20 seconds
Sympathetic Nervous System
Captions available
The idea
The sympathetic nervous system drives the "fight or flight" response, accelerating heart rate and inhibiting digestion to prepare the body for exertion under threat.
In practice
Postganglionic sympathetic neurons release norepinephrine on target organs, while the adrenal medulla adds more into circulation.
Where people slip
Sympathetic activation is pervasive by design — one preganglionic neuron's amplified reach produces a whole-body rush, not a local effect.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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