Splanchnic Nerves

Front 1

Visceral structures

Back 1

Mucous membranes
Glands
Smooth muscle
Cardiac muscle

Front 2

Somatic motor/general sensory

Back 2

Innervate skeletal muscle

Motor: cell bodies in ventral horn
Sensory: cell bodies in DRG

Front 3

Visceral motor fibers (general)

Back 3

Spinal cord --> ganglion --> glands, smooth muscle, cardiac muscle

Front 4

Autonomic NS

Back 4

Visceral motor system; two neuron system

Sympathetic (thoracolumbar)
Parasympathetic (craniosacral)

Front 5

Sympathetic NS

Back 5

Thoracolumbar (T1-L2)
Short pre-ganglionic neuron
Long post-ganglionic neuron
Synapse in para or prevertebral ganglia
Postsynaptic NT: norepinephrine

Front 6

Parasympathetic NS

Back 6

Craniosacral (III, VII, IX, and X and S2-4)
Long pre-ganglionic neuron
Short post-ganglionic neuron
Synapses in wall of organ (usually)
Postsynaptic NT: Acetylcholine
REsponse: feed/breed, vegetate/meditate

Front 7

Sympathetic chain

Back 7

If outside T1-L2, have to ascend or descend

Synapse at the level where exit

Front 8

Splanchnic nerves

Back 8

Can synapse either in prevertebral ganglia or in sympathetic chain

Front 9

Innervation of the heart

Back 9

T1-T4

Sympathetic: above diaphragm, so still synapse on sympathetic chain
Both cervical and thoracic sympathetic cardiac nerves

Parasympathetic: vagus --> cardiac plexus (ganglion)--> heart

Pain conveyed via visceral sensory (one neuron system); retraces sympathetic pathway, synapse in DRG, enter dorsal horn

Reflex information --> vagus (X)--> brain (info about heart rate, e.g.)

Front 10

Referred pain

Back 10

CNS perceives visceral pain from the heart as somatic pain from the T1-T4 dermatome

Front 11

Innervation of the trachea/bronchi

Back 11

T1-T4

Sympathetic: pass through sympathetic chain at thoracic and cervical levels; innervate lungs

Parasympathetic: vagus (X)--> pulmonary plexus --> lungs

Front 12

Innervation of the foregut

Back 12

T5-T9
Sympathetic: bypass sympathetic chain through greater thoracic splanchnic nerve -> celiac ganglion -> foregut
Parasympathetic: vagus --> wall of organ --> organ

Front 13

Celiac ganglia block

Back 13

Used for tumors from pancreas, stomach, duodenum, proximal bowel, liver, and biliary tract

Injection of EtOH, contrast, and saline with needle via anterior approach under CT guidance; block sensory info from this region

Front 14

Innervation midgut and kidney

Back 14

T10-T11
Sympathetic: lesser splanchnic nerve --> aorticorenal and superior mesenteric ganglion --> midgut/kidney
Parasympathetic: vagus --> wall of organ --> organ

Front 15

Innervation of the hindgut

Back 15

Sympathetic: L1-L2
Lumbar splanchnic nerves --> inferior mesenteric ganglion --> hindgut

Parasympathetic: S2-S4
Pelvic splanchnic nerves --> wall of organ --> organ

Front 16

Hirschsprung's Disease

Back 16

Congenital aganglionic megacolon

Birth defect in which large nerve cells that control peristalsis in wall of lg intestine don't develop

Muscles in large intestine do not relax; waste cannot move through L.I. --> trapped stool, infection, inflammation, constipation

Surgical removal of part of colon

Front 17

Innervation of Suprarenal gland

Back 17

No parasympathetic innervation

Direct supply by preganglionic sympathetic neurons (one-neuron)

Front 18

Paravertebral/prevertebral ganglia

Back 18

Paravertebral = collateral

Prevertebral = preaortic

Front 19

Bottom line

Back 19

A splanchnic nerve that exerts its influence in thorax synapses in the sympathetic chain

Splanchnic nreve that exerts its influence in abdomen synapses in a prevertebral ganglion

(Parasympathetic below the diaphragm synapse on wall of organ; above the diaphragm pass through cardiac or pulmonary plexus via vagus)