ORGANIZATION OF THE AUTONOMIC NERVOUS SYSTEM I: OVERVIEW, SOMATIC AND THORACIC PATHWAYS

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Master Class
Autonomic Nervous System
Robert Fisk, Ph.D., James Nemitz, Ph.D., John
Nolte, Ph.D., Britt Sanford, M.D.
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Thoracolumbar Outflow Sympathetic Ganglia and
Attendant Pathways

• James W. Nemitz, Ph.D.
• April 1, 2006
• American Association of Anatomists

Images used in this presentation are taken from
Clinically Oriented Anatomy, 5th Ed., Moore and
Dalley, with permission from the publisher
Lippincott Williams Wilkins.
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Thoracolumbar ANS Sympathetic Nervous System
Postsynaptic (Postganglionic) Sympathetic Neurons
Paravertebral and Prevertebral
(Preaortic/Collateral) Ganglia
Presynaptic (Preganglionic) Sympathetic Neurons
Intermediolateral cell column (IML)
Images taken from Clinically Oriented Anatomy,
5th Ed., Moore Dalley, Lippincott, Williams
Wilkins, 2006.
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Presynaptic Sympathetic Neurons Intermediolateral
Cell Column (IML)

• Location of ALL Presynaptic Sympathetic Cell
  Bodies
• Lateral Horn of Spinal Cord Gray Matter
• Spinal Cord Segments T1 -gt L2,3

IML Somatotopically Organized
Image taken from Clinically Oriented Anatomy
Image, 5th Ed., Moore Dalley, Lippincott
Williams Wilkins, 2006.
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Postsynaptic Sympathetic Neurons Paravertebral
vs. Prevertebral Ganglia

• Sympathetic Ganglia
• Paravertebral Ganglia
• Sympathetic Chain of Ganglia
• Ganglia (Postsynaptic Neurons)
• Sympathetic Trunks (Axons)
• Somatic and Thoracic Pathways
• Prevertebral Ganglia
• Preaortic/Collateral Ganglia (Postsynaptic
  Neurons)
• Abdominal/Pelvic Pathways

Image taken from Clinically Oriented Anatomy, 5th
Ed., Moore Dalley, Lippincott Williams
Wilkins, 2006.
Image taken from Clinically Oriented Anatomy, 5th
Ed., Moore Dalley, Lippincott Williams
Wilkins, 2006.
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Sympathetic Pathways Presynaptic

• Presynaptic Axons
• Ventral Roots and Rami T1-L2,3
• White Rami Communicantes T1-L2,3
• All Presynaptic Axons Enter the Chain
• Synapse Within Sympathetic Chain (Paravertebral
  Ganglia)
• At Entrance Level
• Higher Level
• Lower Level
• Synapse Outside Sympathetic Chain
• (Prevertebral/Preaortic Ganglia)

Image taken from Clinically Oriented Anatomy
Image Collection, 4th Ed., Moore Dalley,
Lippincott Williams Wilkins, 2000.
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Postsynaptic Pathways Parietal

• Somatic Pathways
• Presynaptic IML (T1 L2,3)-gtVentral
  Roots/Rami-gtWhite Rami Communicans -gtSympathetic
  Chain
• Postsynaptic Paravertebral Ganglia -gt Grey
  Rami Communicans -gt Ventral and Dorsal Rami of
  Spinal Nerves (C1 -Coccygeal)
• End Organs in Somatic Structures
• Blood Vessels
• Sweat Glands
• Erector Pilae MM
• Perineal Structures

Image taken from Clinically Oriented Anatomy, 5th
Ed., Moore Dalley, Lippincott Williams
Wilkins, 2006.
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Postsynaptic Pathways Head and Neck

• Head Pathway
• IML (T1-5)
• Superior Cervical Ganglion
• Periarterial plexus
• End Organs
• Dilator pupillae m.
• Superior tarsal m.
• Blood vessels
• Sweat glands

• Neck Pathway
• IML (T1-5)
• Superior, Middle and Inferior Cervical Ganglia
• Grey Rami Communicans
• Cervical Spinal Nerves (C1-C4)
• End Organs
• Blood vessels
• Sweat glands

Image taken from Clinically Oriented Anatomy, 5th
Ed., Moore and Dalley, Lippincott Williams
Wilkins, 2006.
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Postsynaptic Pathways Visceral

• Visceral Pathways
• Input White Rami Communicantes
• T1-L2,3
• Output Splanchnic Nerves
• Cardiopulmonary (Paravertebral Gang.)
• Abdominopelvic (Prevertebral Gang.)
• End Organs
• Visceral Organs

Image taken from Clinically Oriented Anatomy, 5th
Ed., Moore Dalley, Lippincott Williams
Wilkins, 2006.
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Sympathetic Innervation of Thoracic Organs

• Thoracic Pathways
• IML (T4-6) Presynaptic neurons
• Ventral roots and rami
• White rami communicans
• Paravertebral ganglia Postsynaptic neurons
• Cardiopulmonary Splanchnic nerves
• Thoracic Plexi
• Cardiac
• Pulmonary
• Esophageal

Image taken from Clinically Oriented Anatomy, 5th
Ed., Moore Dalley, Lippincott Williams
Wilkins, 2006.
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Sympathetic Innervation of Abdominal Organs

• Abdominal Pathways
• IML (T7-11) presynaptic
• Ventral Roots and Rami
• White Rami Communicans
• Abdominopelvic Splanchnic Nerves (presynaptic
  axons)
• Thoracic
• Lumbar
• Prevertebral Ganglia (postsynaptic neurons)
• Celiac
• Aorticorenal
• Mesenteric
• Postsynaptic axons
• Abdominal Vessels

Image taken from Clinically Oriented Anatomy, 5th
Ed., Moore Dalley, Lippincott, Williams
Wilkins, 2006.
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Suprarenal Gland
Image taken from Clinically Oriented Anatomy, 5th
Ed., Moore and Dalley, Lippincott Williams
Wilkins, 2006.
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Sympathetic Innervation of Pelvic Organs

• Pelvic Pathways
• IML (T12-L2,3) presynaptic neurons
• Ventral roots and rami
• White rami communicans
• Lumbar Splanchnic Nerves (presynaptic axons)
• Prevertebral ganglia (postsynaptic neurons)
• Inferior Mesenteric
• Hypogastric
• Pelvic
• Postsynaptic axons
• Abdominal vessels
• Pelvic vessels

Image taken from Clinically Oriented Anatomy, 5th
Ed., Moore and Dalley, Lippincott Williams
Wilkins, 2006.
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Splanchnic Nerves/Prevertebral Ganglia

• Abdominopelvic Splanchnic Nerves (Presynaptic
  Axons)
• Thoracic
• Greater T5-T9
• Lesser T10-T11
• Least T12
• Lumbar L1-L2

• Prevertebral Ganglia (Postsynaptic Neurons)
• Celiac
• Aorticorenal
• Superior mesenteric
• Inferior mesenteric
• Plexi ganglia

Image taken from Clinically Oriented Anatomy, 5th
Ed., Moore and Dalley, Lippincott Williams
Wilkins, 2006.
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Splanchnic Nerves/Prevertebral Ganglia/Plexi
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Abdominal/Pelvic Plexi

• Celiac Plexus Stomach, Liver, Duodenum,
  Pancreas, Spleen
• Aorticorenal Plexus Kidneys, Suprarenal glands
• Mesenteric Plexi
• Superior Small and Large intestine to splenic
  flexure
• Inferior Large intestine distal to splenic
  flexure
• Hypogastric/Pelvic Plexi
• Superior Pelvic organs
• Inferior Pelvic organs

Images taken from Clinically Oriented Anatomy,
5th Ed., Moore Dalley, Lippincott, Williams
Wilkins, 2006.
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Abdominal/Pelvic Plexi Axonal Components

• Axonal Components
• Sympathetic
• Presynaptic
• Postsynaptic
• Parasympathetic
• Presynaptic
• Visceral Afferents

Image taken from Clinically Oriented Anatomy, 5th
Ed., Moore Dalley, Lippincott, Williams
Wilkins, 2006.
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Referred Pain Abdominal/Pelvic Organs

• Referred Pain Pathway
• Visceral Afferents in Abdominopelvic Splanchnic
  Nerves
• Dorsal Root Ganglia Sensory Cell Bodies
• Spinal Cord Segments and Ganglia Levels

Image taken from Clinically Oriented Anatomy, 5th
Ed., Moore and Dalley, Lippincott Williams
Wilkins, 2006.
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Visceral Afferents

• General Visceral Afferents (GVA)
• Found in sympathetic nerves
• Cell bodies located in Dorsal Root Ganglia
• Synapse in Spinal Cord Dorsal Gray
• Referred Pain
• Viscerosomatic Reflexes

Image taken from Clinically Oriented Anatomy, 5th
Ed., Moore Dalley, Lippincott Williams
Wilkins, 2006.