Anatomy › Help with Parasympathetic Preganglionic Physiology
How is the parasympathetic branch of the autonomic nervous system organized?
Long preganglionic fiber, short postganglionic fiber
Short preganglionic fiber, long postganglionic fiber
Short preganglionic fiber, short postganglionic fiber
Long preganglionic fiber, long postganglionic fiber
Cell bodies of preganglionic neurons are located in the central nervous system (CNS); they synapse onto autonomic ganglia. Parasympathetic ganglia are located in or near the effector organs giving them long preganglionic fibers and short postganglionic fiber. Sympathetic ganglia are located in the paravertebral chain, thus they have short preganglionic fibers and long postganglionic fibers.
What neurotransmitter is used by the preganglionic and postganglionic neurons of the parasympathetic nervous system, respectively?
preganglionic uses acetylcholine; postganglionic uses acetylcholine
preganglionic uses norepinephrine; postganglionic uses acetylcholine
preganglionic uses norepinephrine; postganglionic uses norepinephrine.
preganglionic uses serotonin; postganglionic uses acetylcholine.
The parasympathetic system only has a preganglionic neuron, which uses acetylcholine as its neurotransmitter.
The parasympathetic nervous system acts oppositely to the sympathetic nervous system, by signaling the activation of relaxation and digestion (increased blood flow to digestive system, pupil constriction, lower heart rate and blood pressure). The parasympathetic nervous system signal is transmitted to the body through a preganglionic neuron and a postganglionic neuron. Both of these use acetylcholine in the parasympathetic nervous system.