Sympathetic From spinal levels 1. Fibers that synapse Adrenergic
T1–L2 along the return to the spinal neurotransmission
ventral root; nerve via a gray ramus increases heart rate,
Reach the chain of to mediate cutaneous increases stroke
sympathetic ganglia piloerection, volume, dilates
via white rami vasoconstriction, and coronary and
communicantes sudomotor (sweat pulmonary arteries
gland) activity- Fibers that do not
synapse pass through
the chain as splanchnic
nerves to synapse in
prevertebral ganglia;
from these ganglia,
postsynaptic neurons
run in perivascular
plexuses to innervate
visceral target tissues
Para- Presynaptic cell Postganglionic cell Cholinergic
sympathetic bodies are located bodies lie in numerous neurotransmission
in the dorsal vagal ganglia close to the decreases heart
nuclei of the brain; target organ rate, decreases
The myelinated stroke volume,
synaptic axons form and produces
cranial nerve X, bronchoconstriction
the vagus nerve
SUMMARY OF AUTONOMIC PATHWAYS
Presynaptic Postsynaptic
Division Pathway Pathway EffectPericardial cavity T1–T5: upper Intercostal nerves T1–T5
and midthorax
Heart T1–T4: upper thorax, Cervical and thoracic splanchnic
postaxial brachium nerves
Thoracic T1–T5: thorax and Thoracic splanchnic nerves
esophagus epigastric region
Diaphragm
Central C3–C5: neck and shoulder Phrenic nerve
Marginal T5–T10: thorax Intercostal nervesPAIN REFERRAL FROM THORACIC VISCERA
Organ Referral Area Pathway52