Autonomic Nervous System of the Gut

F.H. Willard, Ph.D.

University of New England

College of Osteopathic Medicine

Innervation of the GI System

• Sympathetic origins:– Thoracic, lumbar and sacral splanchnic n.

– Celiac, superior and inferior mesenteric and hypogastric ganglia

• Parasympathetic origins:– Vagus nerve and pelvic splanchnic nerves

• Enteric Nervous System– Myenteric ganglia

– Submucosal ganglia

Prevertebral Ganglia

• Abdomen– Celiac ganglia– Superior mesenteric ganglia– Inferior mesenteric ganglia

• Pelvis– Hypogastric ganglia

The Celiac Territory:The Foregut

• Distal esophagus, stomach and proximal duodenum

• Pancreas, liver and gall bladder

• Spleen

Celiac Innervation

• Sympathetic innervation– Spinal segments T6 to T9

• Parasympathetic innervation– Vagus nerve

The Superior Mesenteric Territory: The Midgut

• Small intestine– Distal duodenum– Jejunum– Ileum

• Proximal large intestine– Cecum– Ascending colon– Transverse colon

Superior Mesenteric Innervation

• Sympathetic nervous system– Spinal cord segments T9-L1

• Parasympathetic nervous system– Vagus nerve

The Inferior Mesenteric Territory: The Hindgut

• The distal large intestine– Descending colon– Sigmoid colon– Rectum

Inferior Mesenteric Innervation

• Sympathetic nervous system– Spinal cord segments L1 to L2

• Parasympathetic nervous system– Pelvic splanchnic nerves from spinal cord

segments S2 to S4

Enteric Ganglia

• Submucosal ganglia and plexus of Meissner

• Myenteric ganglia and plexus of Auerbach

The Great Abdominopelvic Plexus

• Extends from thoracoabdominal diaphragm to pelvic diaphragm

• Sympathetic origins from T5-L2• Parasympathetic origins from the vagus

nerve and the pelvic splanchnic nerves (S2-S4)

• Sensory input to the spinal cord T5-L2 and S2-S4

Sympathetic Parasympathetic

CGSMG

IMG

HG

Great Abdomino-Pelvic Plexus

Abdomen

Pelvis

ThoracicSplanchnic

N.

Sympathetic Parasympathetic

CGSMG

IMG

HG

Great Abdomino-Pelvic Plexus

Abdomen

Pelvis

ThoracicSplanchnic

N.

LumbarSplanchnic

N.

Sympathetic Parasympathetic

CGSMG

IMG

HG

Great Abdomino-Pelvic Plexus

Abdomen

Pelvis

ThoracicSplanchnic

N.

SacralSplanchnic

N.

LumbarSplanchnic

N.

Sympathetic Parasympathetic

CGSMG

IMG

HG

Great Abdomino-Pelvic Plexus

Abdomen

Pelvis

ThoracicSplanchnic

N.

SacralSplanchnic

N.

VagusNerve

LumbarSplanchnic

N.

Sympathetic Parasympathetic

CGSMG

IMG

HG

Great Abdomino-Pelvic Plexus

Abdomen

Pelvis

ThoracicSplanchnic

N.

SacralSplanchnic

N.

VagusNerve

PelvicSplanchnic

N.

LumbarSplanchnic

N.

Sympathetic Parasympathetic

CGSMG

IMG

HG

Great Abdomino-Pelvic Plexus

Abdomen

Pelvis

Origin BloodSupply

SympatheticInnervation

Para-sympatheticInnervation

Lymphatic Drainage

Foregut Celiac

Artery

Celia

Ganglia

T5-T9

Vagus

Nerve

Celiac Lymph

Nodes

Midgut Superior

Mesenteric

Artery

Superior

Mesenteric

Ganglia

T9-T12

Vagus

Nerve

Superior

Mesenteric

Lymph Nodes

Hindgut Inferior

Mesenteric

Artery

Inferior

Mesenteric

Ganglia

L1-L2

Pelvic

Splanchnic

Nerves

S2-S4

Inferior

Mesenteric

Lymph nodes

The Enteric Nervous System

• Auerbach’s ganglia and plexus– Myenteric plexus

• Motor coordination for peristalsis

• Meissner’s ganglia and plexus– Submucosal plexus

• Sensory integration for both plexuses

• Secretomotor coordination for the gut wall

Referred Abdominal Pain

• Celiac or foregut territory: T5-T9– Upper right and left quadrant pain– Midback pain

• Superior or midgut mesenteric territory: T9-L1– Central or periumbilical pain– Thoracolumbar junction and above

• Inferior or hindgut mesenteric territory: L1-L2 (S2-S4)– Groin and retropubic pain– Thoracolumbar junction and below– Sacral Pain