1. Parasympathetic Sympathetic Eye Eye Brain stem Salivary glands Skin*
Figure Overview of the subdivisions of the autonomic nervous system.
Parasympathetic
Sympathetic
Eye
Eye
Brain stem
Salivary
glands
Skin*
Cranial
Salivary
glands
Sympathetic
ganglia
Heart
Cervical
Lungs
Lungs
Heart T1
Stomach
Stomach
Small
intestine
Thoracic
Pancreas
and small
intestine
Pancreas
Liver and gall-
bladder
Liver and
gall-
bladder L1
Adrenal
gland
Lumbar
Large
intestine
Large
intestine
Bladder
Bladder
Genitals
Sacral
Genitals

2. Figure 20.2 Sympathetic trunks and pathways.
Lateral horn
(visceral motor zone)
Dorsal root
Spinal cord
Dorsal root ganglion
Dorsal root
ganglion
Dorsal ramus of
spinal nerve
Ventral root
Ventral ramus of
spinal nerve
Rib
Gray ramus
communicans
Ventral root
Sympathetic
trunk ganglion
Sympathetic
trunk ganglion
White ramus
communicans
Sympathetic trunk
Sympathetic
trunk 1
Synapse at the same level
Ventral ramus
of spinal nerve
Gray ramus
communicans
White ramus
communicans
Thoracic
splanchnic nerves
Location of the sympathetic trunk 2
Synapse at a higher or lower level
Skin (arrector
pili muscles
and sweat
glands)
Effectors
Blood vessels
Splanchnic nerve
Collateral ganglion
(such as the celiac)
Abdominal
organs
(e.g., intestine)
Synapse in a distant
collateral ganglion anterior
to the vertebral column 3
Three pathways of a sympathetic innervation 2