Medical Gross Anatomy
Anatomy Tables - Nerves
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Medical Gross Anatomy |
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Nerves of the Thoracic Region - Listed Alphabetically |
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| Nerve | Source | Branches | Motor | Sensory | Notes |
| cardiac plexus | cardiac brs. of the vagus n. and cervical sympathetic trunk; thoracic visceral nn. | no named branches | moderates heart muscle (parasympathetic: decreases rate and force of contraction; sympathetic: increases rate and force of contraction); vascular smooth muscle of the heart & lungs (sympathetic); smooth muscle & mucous glands of bronchial tree (parasympathetic) | pain from the heart and lungs | cardiac plexus is continuous with the coronary and pulmonary plexuses; thoracic visceral nn. carry pain from the heart to the upper thoracic spinal cord segments resulting in pain referred to the left upper limb in the T1 and T2 dermatomes |
| cardiac, sympathetic | cervical sympathetic trunk | no named branches | heart (sympathetic: increases rate and force of contraction, parasympathetic: decreases rate and force of contraction); bronchial tree & lungs via pulmonary plexus | heart, bronchial tree and lungs | cervical sympathetic trunk usually gives 3 cervical cardiac brs. l (superior, middle and inferior) to the cardiac plexus |
| cardiac, vagal | vagus n. (X) | no named branches | heart (parasympathetic: decreases rate and force of contraction; sympathetic: increases rate and force of contraction); bronchial tree and lungs via pulmonary plexus | heart, bronchial tree and lungs | vagus n. has 2 cervical cardiac brs. (superior and inferior) and 1 or more thoracic cardiac brs. |
| dorsal primary ramus | first branch off of the dorsal side of the spinal nerve | numerous | to the deep back mm.; sympathetic innervation to the skin | general sense (touch, pressure, pain, heat, cold, etc.) to the skin of the back | a mixed nerve containing both motor and sensory fibers |
| dorsal root | from the dorsal horn of the spinal cord to the spinal nerve | none | none | general sense (touch, pressure, pain, heat, cold, etc.) | dorsal root is entirely sensory in function; it is located dorsal to the denticulate ligament |
| dorsal root ganglion | dorsal rootlets | dorsal rootlets | none | one dermatome | a sensory ganglion; located in the intervertebral foramen of the vertebral column on the dorsal root - one per spinal nerve; location of the cell bodies of somatic afferent (sensory) neurons |
| esophageal plexus | right and left vagus (X) nn.; thoracic visceral brs. of the sympathetic trunk | anterior and posterior vagal trunks | preganglionic parasympathetic axons from the vagus n. supply smooth muscle and glands of the thoracic esophagus and abdominal gut and its derivatives proximal to the left colic flexure; postganglionic sympathetic axons from the thoracic visceral brs. supply vascular smooth muscle in the esophageal vessels | vagus: GVA from the esophagus and abdominal gut proximal to the left colic flexure; thoracic visceral brs.carry pain from the esophagus | during development of the gut, the stomach and esophagus rotate 90° to the right with the result that the left and right vagus nerves mix in the esophageal plexus and emerge as anterior and posterior vagal trunks |
| ganglia, sympathetic chain | preganglionic sympathetic fibers arrive via white rami communicantes of ventral primary rami of spinal nerves T1-L2 | postganglionic sympathetic fibers depart via gray rami communicantes to all spinal nn.; internal & external carotid nn.; cervical cardiac brs.; thoracic direct visceral brs.; greater, lesser & least thoracic splanchnic nn.; lumbar splanchnic nn.; sacral splanchnic nn. | dilator pupillae, vascular smooth muscle, arrector pili muscles, sweat glands, suprarenal medulla, heart, lungs and gut | pain from viscera | located lateral to the vertebral bodies in the neck, thorax & abdominopelvic cavity; the ganglia plus their interconnecting fibers are also known as the sympathetic trunk; preganglionic cell bodies are located in the intermediolateral gray matter of spinal cord levels T1-L2 |
| ganglion, dorsal root | dorsal rootlets | dorsal rootlets | none | one dermatome | a sensory ganglion; located in the intervertebral foramen of the vertebral column on the dorsal root - one per spinal nerve; location of the cell bodies of somatic afferent (sensory) neurons |
| gray ramus communicans | cell bodies located in the sympathetic chain ganglia | none | carries postganglionic sympathetic axons to the spinal nerve; spinal nerve will carry those axons peripherally to the skin, blood vessels, etc. | none | gray rami communicantes connect the sympathetic chain to spinal nerves at all vertebral levels |
| greater thoracic splanchnic n. | neurons in the intermediolateral cell column of spinal cord levels T5-T9; the greater thoracic splanchnic nerve appears to arise by multiple contributions from the sympathetic trunk | no named branches | celiac ganglion; preganglionic fibers supply the adrenal medulla which releases epinephrine and norepinephrine into the blood | pain from the abdominal viscera | greater thoracic splanchnic n. passes through the crus of the respiratory diaphragm; postganglionic processes from the celiac ganglion spread down the aorta and distribute with its branches; they innervate the vascular smooth of these vessels and vascular smooth muscle of the organs supplied |
| intercostal n. | ventral primary rami of spinal nerves T1-T11 | lateral & anterior cutaneous brs. | intercostal muscles; abdominal wall muscles (via T7-T11); muscles of the forearm and hand (via T1) | skin of the chest and abdomen anterolaterally; skin of the medial side of the upper limb (via T1-T2) | intercostal n.travels below the posterior intercostal a. in the costal groove |
| intercostobrachial n. | also known as the lateral cutaneous br. of the ventral primary ramus of T2 | no named branches | sympathetic motor innervation to skin | skin of the medial side of the arm | intercostobrachial n. communicates with the medial brachial cutaneous nerve |
| intermediate supraclavicular n. | cervical plexus (C3&C4) | no named branches | none | skin of the root of the neck and upper chest, near the mid-clavicle | pain from respiratory diaphragm is referred to the shoulder |
| lateral supraclavicular n. | cervical plexus (C3&C4) | no named branches | none | skin of the root of the neck and upper shoulder | pain from respiratory diaphragm is referred to the shoulder |
| least thoracic splanchnic n. | neurons in the intermediolateral cell column of spinal cord level T12 | no named branches | renal plexus | pain from the kidney and suprarenal gland | least thoracic splanchnic n.pass through the crus of the diaphragm; it synapses in minute ganglia located in the renal plexus |
| lesser thoracic splanchnic n. | neurons in the intermediolateral cell column of spinal cord levels T10-T11; the lesser thoracic splanchnic nerve appears to arise by multiple contributions from the sympathetic trunk | no named branches | aorticorenal ganglion; | pain from the kidney and suprarenal gland | lesser thoracic splanchnic n. passes through the crus of the respiratory diaphragm; postganglionic processes from the ganglion supply vascular smooth muscle of branches of the renal a. and suprarenal aa.; kidney and suprarenal gland |
| medial supraclavicular n. | cervical plexus (C3&C4) | no named branches | none | skin of the root of the neck and upper chest, anteriorly | pain from respiratory diaphragm is referred to the shoulder |
| phrenic n. | ventral primary rami of spinal nerves C3-C5 (cervical plexus) | no named branches | skeletal muscle of the respiratory diaphragm | diaphragmatic pleura; some fibers contributed to the pericardium and to the adjacent mediastinal and costal pleurae | phrenic n. crosses the anterior surface of the anterior scalene m. |
| plexus, cardiac | cardiac brs. of the vagus n. and cervical sympathetic trunk; thoracic visceral nn. | no named branches | moderates heart muscle (parasympathetic: decreases rate and force of contraction; sympathetic: increases rate and force of contraction); vascular smooth muscle of the heart & lungs (sympathetic); smooth muscle & mucous glands of bronchial tree (parasympathetic) | pain from the heart and lungs | cardiac plexus is continuous with the coronary and pulmonary plexuses; thoracic visceral nn. carry pain from the heart to the upper thoracic spinal cord segments resulting in pain referred to the left upper limb in the T1 and T2 dermatomes |
| plexus, esophageal | right and left vagus (X) nn.; thoracic visceral brs. of the sympathetic trunk | anterior and posterior vagal trunks | preganglionic parasympathetic axons from the vagus n. supply smooth muscle and glands of the thoracic esophagus and abdominal gut and its derivatives proximal to the left colic flexure; postganglionic sympathetic axons from the thoracic visceral brs. supply vascular smooth muscle in the esophageal vessels | vagus: GVA from the esophagus and abdominal gut proximal to the left colic flexure; thoracic visceral brs.carry pain from the esophagus | during development of the gut, the stomach and esophagus rotate 90° to the right with the result that the left and right vagus nerves mix in the esophageal plexus and emerge as anterior and posterior vagal trunks |
| plexus, pulmonary | continuous with the cardiac plexus; thoracic visceral nn.; pulmonary brs. of vagus | no named branches | parasympathetic: smooth muscle & glands of the bronchial tree; sympathetic: vascular smooth muscle of the lungs | none | pulmonary plexus is located along the pulmonary vessels and primary bronchi in the root of the lung |
| preaortic ganglia | splanchnic nn. | plexuses to abdominal and pelvic viscera | vascular smooth muscle of vessels that supply abdominopelvic viscera | pain from abdominopelvic viscera | also known as: collateral ganglia which include the celiac ganglion, aorticorenal ganglion, superior mesenteric ganglion and inferior mesenteric ganglion; preganglionic parasympathetic axons of vagal trunk origin pass through the preaortic ganglia but do not synapse there |
| ramus communicans, gray | cell bodies located in the sympathetic chain ganglia | none | carries postganglionic sympathetic axons to the spinal nerve; spinal nerve will carry those axons peripherally to the skin, blood vessels, etc. | none | gray rami communicantes connect the sympathetic chain to spinal nerves at all vertebral levels |
| ramus communicans, white | cell bodies located in the lateral horn gray matter of spinal cord levels T1-L2; | none | axons contained within white rami communicantes will synapse on postganglionic cell bodies that will ultimately innervate the skin, viscera, glands, blood vessels, etc. | pain from viscera is carried back to the spinal cord through the white ramus communicans | white rami communicantes connect the sympathetic chain to spinal nerves at vertebral levels T1-L2; carries preganglionic sympathetic axons |
| ramus, dorsal primary | first branch off of the dorsal side of the spinal nerve | numerous | to the deep back mm.; sympathetic innervation to the skin | general sense (touch, pressure, pain, heat, cold, etc.) to the skin of the back | a mixed nerve containing both motor and sensory fibers |
| ramus, ventral primary | first branch off of the ventral side of the spinal nerve | numerous | to skeletal mm. of the neck, trunk and extremities; sympathetic innervation to the skin | general sense (touch, pressure, pain, heat, cold, etc.) to the skin of the trunk (except the back) and extremities; visceral pain via the white rami of the sympathetic nervous system (T1-L2) | a mixed nerve containing both motor and sensory fibers |
| root, dorsal | from the dorsal horn of the spinal cord to the spinal nerve | none | none | general sense (touch, pressure, pain, heat, cold, etc.) | dorsal root is entirely sensory in function; it is located dorsal to the denticulate ligament |
| root, ventral | from the ventral horn of the spinal cord to the spinal nerve | none | to skeletal mm.; preganglionic sympathetic (T1-L2) | none | entirely motor in function; located ventral to the denticulate ligament; at all spinal core levels it contains GSE for skeletal mm.; at levels T1-L2 it contains GVE (preganglionic sympathetic) for blood vessels, sweat glands, thoracic viscera, abdominal viscera, pelvic viscera |
| splanchnic, greater thoracic | neurons in the intermediolateral cell column of spinal cord levels T5-T9; the greater thoracic splanchnic nerve appears to arise by multiple contributions from the sympathetic trunk | no named branches | celiac ganglion; preganglionic fibers supply the adrenal medulla which releases epinephrine and norepinephrine into the blood | pain from the abdominal viscera | greater thoracic splanchnic n. passes through the crus of the respiratory diaphragm; postganglionic processes from the celiac ganglion spread down the aorta and distribute with its branches; they innervate the vascular smooth of these vessels and vascular smooth muscle of the organs supplied |
| splanchnic, least thoracic | neurons in the intermediolateral cell column of spinal cord level T12 | no named branches | renal plexus | pain from the kidney and suprarenal gland | least thoracic splanchnic n.pass through the crus of the diaphragm; it synapses in minute ganglia located in the renal plexus |
| splanchnic, lesser thoracic | neurons in the intermediolateral cell column of spinal cord levels T10-T11; the lesser thoracic splanchnic nerve appears to arise by multiple contributions from the sympathetic trunk | no named branches | aorticorenal ganglion; | pain from the kidney and suprarenal gland | lesser thoracic splanchnic n. passes through the crus of the respiratory diaphragm; postganglionic processes from the ganglion supply vascular smooth muscle of branches of the renal a. and suprarenal aa.; kidney and suprarenal gland |
| stellate ganglion | neurons in the intermediolateral cell column of spinal cord level T1 | gray rami communicans to spinal nerves C8 and T1 (postganglionic sympathetic); thoracic visceral br. | vascular smooth muscle, arrector pili muscle, sweat glands of the C8 & T1 cutaneous distribution on chest & upper limb (C8 and T1 dermatomes); vascular smooth muscle of the lungs | pain from lungs | stellate ganglion is formed by the fusion of the inferior cervical sympathetic ganglion and the T1 ganglion of the sympathetic trunk |
| supraclavicular, intermediate | cervical plexus (C3&C4) | no named branches | none | skin of the root of the neck and upper chest, near the mid-clavicle | pain from respiratory diaphragm is referred to the shoulder |
| supraclavicular, lateral | cervical plexus (C3&C4) | no named branches | none | skin of the root of the neck and upper shoulder | pain from respiratory diaphragm is referred to the shoulder |
| supraclavicular, medial | cervical plexus (C3&C4) | no named branches | none | skin of the root of the neck and upper chest, anteriorly | pain from respiratory diaphragm is referred to the shoulder |
| sympathetic chain ganglia | preganglionic sympathetic fibers arrive via white rami communicantes of ventral primary rami of spinal nerves T1-L2 | postganglionic sympathetic fibers depart via gray rami communicantes to all spinal nn.; internal & external carotid nn.; cervical cardiac brs.; thoracic direct visceral brs.; greater, lesser & least thoracic splanchnic nn.; lumbar splanchnic nn.; sacral splanchnic nn. | dilator pupillae, vascular smooth muscle, arrector pili muscles, sweat glands, suprarenal medulla, heart, lungs and gut | pain from viscera | located lateral to the vertebral bodies in the neck, thorax & abdominopelvic cavity; the ganglia plus their interconnecting fibers are also known as the sympathetic trunk; preganglionic cell bodies are located in the intermediolateral gray matter of spinal cord levels T1-L2 |
| vagus n. | medulla: dorsal motor nucleus (GVE preganglionic parasympathetic); inferior ganglion (GVA); nucleus ambiguus (SVE); superior ganglion (GSA); inferior ganglion(SVA) | auricular br., pharyngeal br., superior laryngeal, superior and inferior cervical cardiac brs., recurrent laryngeal n., thoracic cardiac brs., brs. to the pulmonary plexus, brs. to the esophageal plexus, anterior and posterior vagal trunks | SVE: intrinsic muscles of the larynx, pharynx (except stylopharyngeus), and palate (except tensor veli palatini); GVE: smooth muscle of the respiratory tree & gut (proximal to the left colic flexure), heart; secretomotor: mucous glands of the larynx, respiratory tree, pharynx and gut; secretomotor to digestive glands | GSA: skin of the external auditory meatus; GVA: viscera of head, neck, thorax & abdomen proximal to the left colic flexure; SVA: taste from the epiglottis | also known as: CN X, 10th cranial nerve; the vagus n. passes through the jugular foramen to exit the posterior cranial fossa; vagus means "wanderer" in reference to its extensive distribution to the body cavities |
| ventral primary ramus | first branch off of the ventral side of the spinal nerve | numerous | to skeletal mm. of the neck, trunk and extremities; sympathetic innervation to the skin | general sense (touch, pressure, pain, heat, cold, etc.) to the skin of the trunk (except the back) and extremities; visceral pain via the white rami of the sympathetic nervous system (T1-L2) | a mixed nerve containing both motor and sensory fibers |
| ventral root | from the ventral horn of the spinal cord to the spinal nerve | none | to skeletal mm.; preganglionic sympathetic (T1-L2) | none | entirely motor in function; located ventral to the denticulate ligament; at all spinal core levels it contains GSE for skeletal mm.; at levels T1-L2 it contains GVE (preganglionic sympathetic) for blood vessels, sweat glands, thoracic viscera, abdominal viscera, pelvic viscera |
| white ramus communicans | cell bodies located in the lateral horn gray matter of spinal cord levels T1-L2; | none | axons contained within white rami communicantes will synapse on postganglionic cell bodies that will ultimately innervate the skin, viscera, glands, blood vessels, etc. | pain from viscera is carried back to the spinal cord through the white ramus communicans | white rami communicantes connect the sympathetic chain to spinal nerves at vertebral levels T1-L2; carries preganglionic sympathetic axons |
| The material presented in these tables is
contained in the book: MedCharts Anatomy by Thomas R. Gest & Jaye Schlesinger Published by ILOC, Inc., New York Copyright © 1995, unauthorized use prohibited. |
The excellent editorial assistance of Dr. Pat Tank, UAMS is gratefully acknowledged. |
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| Copyright© 2000 The University of Michigan. Unauthorized use prohibited. |
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