Parasympathetic Nervous System

Parasympathetic nick name

rest and digest

preganglionic parasympathetic neurons

cranial nerves and spinal nerves

cranial nerves

CN3, CN7, CN9, stay in head except for CN10

CN3

eye

CN7

tears, saliva, nasal glands

CN9

saliva glands

CN10

vagus nerve

vagus nerve

not in the spine, in the esophagus, lungs, heart, abdominal organs, GI tract

parasympathetic spinal preganglionic neurons

S1 to S4, colon, rectum, bladder, gentalia

the axons of preganglionic parasympathetic neurons are

long and myelinated, B fibers

postganglionic parasympathetic neurons are

short, usually in wall of tissue, unmyelinated C fibers

NT and receptor in between parasympathetic preganglionic and postganglionic neuron

ACh and nNAChR

NT and receptor in between postganglionic neuron and tissue

ACh, muscarinic cholinergic

receptor types in parasympathetic nervous system

muscarinic cholinergic

muscarinic cholinergic receptor types

m2AChR and m3AChR

m2ACh receptor

lowers heartrate

m3ACh receptor

bronchoconstriction, bladder contraction, uterine contraction, increased motility and digestion in GI tract, increased gland secretion, pupil constriction, near vision focus

Can ACh be released as a hormone?

No hormonal release of ACh

How is acetyl choline broken down in the parasympathetic system?

acetylcholine esterase