Medical Gross Anatomy
Anatomy Tables - Nerves
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Medical Gross Anatomy |
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Nerves of the Back Region - Listed Alphabetically |
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| Nerve | Source | Branches | Motor | Sensory | Notes |
| accessory | cranial root: medulla - nucleus ambiguus; spinal root: spinal nucleus of the upper cervical spinal cord | no named branches | GSE: sternocleidomastoid and trapezius mm. | none | also known as: CN XI, 11th cranial nerve; spinal root enters cranial cavity by passing through the foramen magnum; exits skull by passing through the jugular foramen; accessory n. is motor only; the subtrapezial plexus of nerves receives proprioceptive fibers: for the sternocleidomastoid m. from the ventral primary rami of spinal nn. C2 and C3 - for trapezius via ventral primary rami of C3 and C4 |
| cluneal, inferior | posterior femoral cutaneous n. | no named branches | none | skin of the lower part of the buttock | "clunis" is a Latin word meaning buttock |
| cluneal, middle | lateral cutaneous branches of the dorsal primary rami of spinal nerves S1-3 | no named branches | none | skin of the intermediate medial portion of the buttock | "clunis" is a Latin word meaning buttock |
| cluneal, superior | lateral cutaneous branches of the dorsal primary rami of spinal nerves S1-3 | no named branches | none | skin of the superomedial portion of the buttock | "clunis" is a Latin word meaning buttock |
| coccygeal plexus | ventral primary rami of spinal nerves S4, S5, C1 | anococcygeal n. | none | skin of the region overlying the coccyx | only part of the S4 ventral primary ramus is contributed to the coccygeal plexus |
| 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 |
| dorsal scapular n. | brachial plexus (br. of C5 ventral primary ramus) | no named branches | rhomboideus major and minor mm.; levator scapulae m. | none | dorsal scapular n. passes through the scalenus medius m. |
| 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 |
| occipital, greater | dorsal primary ramus of spinal nerve C2 (medial br.) | no named branches | posterior neck muscles | skin of the posterior surface of the scalp | muscles innervated by this nerve develop from epimeres in the embryo |
| occipital, lesser | ventral primary ramus of spinal nerve C2 | no named branches | none | skin behind the ear | lesser occipital n. arises from the cervical plexus |
| occipitalis tertius | dorsal primary ramus of spinal nerve C3 (medial br.) | no named branches | posterior neck muscles | skin of the posterior surface of the neck | muscles innervated by this nerve develop from epimeres in the embryo |
| 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 |
| spinal n. | formed at the point where the dorsal and ventral rootlets meet; it ends where the dorsal and ventral primary rami diverge | dorsal primary ramus; ventral primary ramus | to skeletal mm.; some levels carry preganglionic sympathetic axons (T1-L2) | general sense (touch, pressure, pain, heat, cold, etc.) from the entire surface of the neck, trunk and extremities; visceral pain (via the white ramus communicans and the sympathetic nervous system) | located at the intervertebral foramen; there are 31 pairs of spinal nerves - 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal |
| 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 |
| 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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