Final answer:
The sympathetic division of the autonomic nervous system manages stress responses using short preganglionic and long postganglionic fibers to modulate organ function. It also interacts with the adrenal medulla for systemic effects. The parasympathetic division has longer preganglionic fibers and shorter postganglionic fibers for rest-and-digest functions.
Step-by-step explanation:
The sympathetic division of the autonomic nervous system governs the body's sympathetic response during situations of stress or emergency, often described as the fight-or-flight response. Preganglionic sympathetic fibers originate from the lateral horn of the thoracolumbar spinal cord and are relatively short and myelinated. They travel to either the sympathetic chain ganglia or to the collateral ganglia where they release acetylcholine (ACh) to excite ganglionic neurons via nicotinic receptors.
Postganglionic sympathetic fibers, which are typically long and unmyelinated, then project from these ganglionic neurons to various target effectors throughout the body, releasing norepinephrine to bind to adrenergic receptors, altering the organ's physiology to match the systemic sympathetic activation. The sympathetic system also communicates directly with the suprarenal medulla to release epinephrine and norepinephrine into the bloodstream for a widespread systemic effect.
By contrast, the parasympathetic division tends to have long preganglionic fibers and short postganglionic fibers, with ganglia close to or within the target effector, modulating rest-and-digest activities.