Anatomy, Head and Neck, Cervical Nerves


Article Author:
Joshua Waxenbaum


Article Editor:
Bruno Bordoni


Editors In Chief:
Michael Labanowski


Managing Editors:
Orawan Chaigasame
Carrie Smith
Abdul Waheed
Frank Smeeks
Kristina Soman-Faulkner
Benjamin Eovaldi
Radia Jamil
Sobhan Daneshfar
Saad Nazir
William Gossman
Pritesh Sheth
Hassam Zulfiqar
Navid Mahabadi
Steve Bhimji
John Shell
Matthew Varacallo
Ahmad Malik
Mark Pellegrini
James Hughes
Beata Beatty
Hajira Basit
Phillip Hynes


Updated:
2/5/2019 10:22:13 PM

Introduction

Cervical nerves are spinal nerves that arise from the cervical region of the spinal cord. These nerves conduct motor and sensory information via efferent and afferent fibers, respectively, to and from the central nervous system. While classified as peripheral nerves, the motor cell body resides in the anterior horn of the spinal cord. There are eight pairs of cervical nerves, denoted C1 to C8, that emerge from the spinal cord superior to their corresponding vertebrae, except for C8 that exits inferiorly to the C7 vertebra. These nerves intertwine through plexuses that give rise to peripheral nerves that maintain a significant motor function in the head, neck, upper limbs and diaphragm, as well as sensation in the head, neck, shoulders and upper limbs in a dermatomal pattern.[1][2][3]

Structure and Function

The cervical nerves arise from the spinal cord in the form of rootlets, or fila radicularia, smaller neuron bundles that coalesce to form roots. For each spinal nerve, an anterior and posterior root join to form the completed nerve.[4] Shortly after branching out of the spinal cord, the cervical nerves form the cervical and brachial plexuses. It is important to note that the inputs and outputs may vary by individual and therefore, different sources may offer different descriptions.[2][5][6]

The cervical plexus forms from the ventral rami of C1 to C4. It is known to anastomose with the facial nerve, hypoglossal nerve, spinal accessory nerve, vagus nerve, and the sympathetic trunk. It lies anteromedial to the scalenes, but is deep to the sternocleidomastoid,[7] and gives rise to the motor and sensory branches:

Motor

  • The C1 spinal nerve gives rise to the nerve to the geniohyoid and the nerve to the thyrohyoid that both function in the oropharynx. Anatomically, these nerves travel closely to the hypoglossal nerve (CN XII).[8]
  • The ansa cervicalis (“handle of the neck” in Latin), is a loop of nerves that lies superficial to the internal jugular vein, composed of the C1 to C3 nerves. More specifically, one end of the loop, the superior root, is derived from C1 (and possibly C2, depending on the literature), while the other, the inferior root, comes from C2 and C3. This structure gives rise to the nerves to the sternohyoid, sternothyroid, and superior and inferior bellies of the omohyoid muscles.[9] All of the muscles supplied by branches of the ansa cervicalis, along with the thyrohyoid, are infrahyoid muscles, and therefore serve to depress the hyoid bone. This function is necessary for proper speech and swallowing.[10]
  • The C3, C4, and C5 roots contribute to form the phrenic nerves. These are responsible for motor and sensory supply to the diaphragm, as well as for sympathetic output. The phrenic nerves run anteriorly to the subclavian arteries, but posterior to the subclavian veins.[7]
  • Outside of the cervical plexus, the several muscles are innervated directly by upper cervical nerve roots[11][12][13]:
    • C1 to C2: Rectus capitis anterior/lateralis
    • C1 to C3/4/5: Longus capitis
    • C2/3 to C4: Trapezius (sensory)

Sensory

  • The cutaneous branches of the cervical plexus transmit sensory information from the skin of the neck, the superior portions of the thorax, and the scalp.[7] These nerves emerge from a common point at the posterior aspect of the sternocleidomastoid, known as Erb’s point.[14] There are several branches:
    • The lesser occipital nerve arises from C2 and supplies the skin of the neck and the scalp posterior and superior to the auricle.
    • The greater auricular nerve, of C2 and C3, ascends anterior to the auricle and supplies the skin over the parotid gland, the mastoid process and the skin from the parotid gland to the mastoid process.
    • The transverse cervical nerve, of C2 and C3, projects posteriorly and wraps around anteriorly to supply the skin of the anterior cervical region.
    • The supraclavicular nerve, of C3 and C4, descend from the posterior sternocleidomastoid and provides sensory information from the skin over the clavicle and shoulder.[1][7]

Sympathetics

  • The ventral rami that compose the cervical plexus each receive gray rami communicantes from the superior cervical ganglion of the sympathetic trunk.[15][16]

The brachial plexus forms from the ventral rami of C5 to C8, as well as T1. The plexus projects laterally, anterior to the first rib, but posterior to the clavicle, into the axillary region. The plexus is divided into several sections through its several anastomoses from the five nerve roots into three trunks, six divisions, three cords, and finally, five branches.[17] The final outputs are best described by the location from which they emerge from the plexus, rather than simply based on their motor/sensory function as several nerves carry both types of information [2][5][6][18]:

  • Roots
    • The C4 and C5 roots give rise to the dorsal scapular nerve that supplies the rhomboids and levator scapulae.
    • C5, as mentioned earlier, along with C3 and C4, contributes to the phrenic nerve that innervates the diaphragm.
    • Roots C5, C6, and C7 produce the long thoracic nerve, responsible for controlling the serratus anterior.
  • Trunks
    • From the upper trunk C5 and C6 give rise to the nerve to the subclavius, and the suprascapular nerve, that supply the subclavius muscle, and the supra- and infraspinatus muscles, respectively.
  • Cords
    • From the lateral cord, C5, C6, and C7 supply the pectoralis major and minor muscles, via the lateral and medial pectoral nerves, as well as the coracobrachialis, brachialis and biceps brachii, via the musculocutaneous nerve. The musculocutaneous nerve provides sensation to the skin of the lateral forearm.
    • These three roots also form the lateral root of the median nerve that controls most forearm flexors, except flexor carpi ulnaris and the medial portion of flexor digitorum profundus, the first and second lumbricals and the muscles of the thenar eminence. This nerve also provides sensation to the palmar aspect of the thumb, index finger, middle finger, and the lateral aspect of the fourth digit.
    • The posterior cord has five outputs:
      • From C5 and C6, the upper and lower subscapular nerves supply the upper and lower portions of the subscapularis. The lower subscapular nerve also innervates teres major.
      • Additionally, from C5 and C6, the axillary nerve supplies the motor function of the deltoid and teres minor, as well as the sensory aspect of the overlying skin, the superior lateral cutaneous nerve of the arm, and the skin of the lateral shoulder and arm.
      • Thoracodorsal nerve originates from C6, C7, and C8, and innervates the latissimus dorsi.
      • Lastly, the radial nerve, which derives from all five roots of the brachial plexus, is responsible for the motor innervation of the triceps brachii, the supinator, the anconeus, the brachioradialis, and all extensor muscles of the forearm. It also supplies the skin of the posterior arm, posterior hand, and the webbing between the thumb and index finger.
    • The medial cord also produces five outputs, all of which derive from C8 and T1:
      • The medial pectoral nerve, which supplies pectoralis minor and part of pectoralis major.
      • The medial root of the median nerve (see the lateral root for details).
      • The medial cutaneous nerves of the arm and forearm are purely sensory and supply the medial skin of arm and forearm, respectively.
      • Lastly, is the ulnar nerve, which provides motor control to the flexor carpi ulnaris, the medial belly of flexor digitorum profundus, the two medial lumbricals, the interossei, and the muscles of the hypothenar eminence. It also provides sensation to the fifth digit, the hypothenar eminence and the medial half of the fourth finger.
    • Branches
      • Musculocutaneous nerve
      • Axillary nerve
      • Radial nerve
      • Median nerve
      • Ulnar nerve

For more detailed coverage of the structure of the brachial plexus, see the associated StatPearls articles referenced, here.[19][20]

Embryology

Spinal nerves originate from the sclerotome, more specifically, the central region of the anterior-half-sclerotome. This portion of the sclerotome is also responsible for the endoneurium and perineurium of the spinal nerves. This origin stands in contrast to the posterior-half-sclerotome that forms the bone and cartilage of the vertebral column. The posterior half also acts to block the outgrowth of neural crest cells and spinal nerve axons, thus leading to the segmentation of the spinal nerves.[21]

Blood Supply and Lymphatics

The roots of spinal nerves receive vascular supply from the radicular arteries. These arteries pass through the intervertebral foramina with the nerve roots. The first six vessels most commonly arise from the vertebral arteries or the ascending cervical branch of the thyrocervical trunk. In either case, the spinal branches of these two vessels anastomose, so if either source has a blockage, blood flow is maintained. The radicular arteries of the seventh and eighth segments always form from branches of the costocervical trunk.[22]

Physiologic Variants

There are numerous variants of cervical nerves and their derivatives that can present in a patient. Specifically, the cervical nerves that contribute to the cervical and brachial plexuses vary between individuals to a significant degree. Moreover, the terminal nerves that branch off the cervical and brachial plexuses may vary in contribution and location of origin.[18]

Clinical Significance

The most common pathology associated with cervical nerves, radiculopathy, is caused most commonly by impingement by spondylosis or disk herniation. This topic is covered in depth by the StatPearls article referenced, here.[23] For more information on the specifics of brachial plexus injuries,[24] as well as other cervical nerve-related pathologies, see the associated StatPearls articles.


  • Image 8485 Not availableImage 8485 Not available
    Henry Vandyke Carter [Public domain]
Attributed To: Henry Vandyke Carter [Public domain]

Interested in Participating?

We are looking for contributors to author, edit, and peer review our vast library of review articles and multiple choice questions. In as little as 2-3 hours you can make a significant contribution to your specialty. In return for a small amount of your time, you will receive free access to all content and you will be published as an author or editor in eBooks, apps, online CME/CE activities, and an online Learning Management System for students, teachers, and program directors that allows access to review materials in over 500 specialties.

Improve Content - Become an Author or Editor

This is an academic project designed to provide inexpensive peer-reviewed Apps, eBooks, and very soon an online CME/CE system to help students identify weaknesses and improve knowledge. We would like you to consider being an author or editor. Please click here to learn more. Thank you for you for your interest, the StatPearls Publishing Editorial Team.

Anatomy, Head and Neck, Cervical Nerves - Questions

Take a quiz of the questions on this article.

Take Quiz
A patient presents with traumatic injury to the cervical spine. Which spinal nerve cannot be tested for injury through an evaluation of dermatomal distribution?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
A librarian presents for follow-up on his upper cervical pain. Which dermatome would be expected to correlate to his pain?

(Move Mouse on Image to Enlarge)
  • Image 4194 Not availableImage 4194 Not available
    Contributed by Wikimedia Commons (Public Domain)
Attributed To: Contributed by Wikimedia Commons (Public Domain)



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
While performing a neurological examination, the patient has an issue with their C8 nerve. With which action did the patient likely display weakness?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
A patient has suspected C7 radiculopathy. What maneuver will help determine what muscles are involved?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
A 42-year-old bartender presents with a cigarette burn of the right forefinger and thumb. The patient states that he was not aware of being burned and that he now notices that he feels no pain or temperature sensations in these fingers. On examination, it is found that the patient indeed has a symmetrical deficiency involving the same fingers of both hands. However, sensations of touch and proprioception are not impaired. In addition, motor functions of these fingers are found to be normal. Where is the lesion is localized?

(Move Mouse on Image to Enlarge)
  • Image 5687 Not availableImage 5687 Not available
    Contributed by the Public Domain
Attributed To: Contributed by the Public Domain



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
The ansa cervicalis sends motor branches to which of the following muscles?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
While repairing a suprascapular artery, a surgeon carefully monitors the patient's vital signs in case she damages a particular nerve. What cervical nerves compose the nerve in question?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
Which cervical spinal nerves give rise to the cutaneous branch that descends from the posterior triangle of the neck to reach the skin below the middle of the clavicle?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
The ansa cervicalis is formed by the ventral primary rami of:



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
A patient had sustained a stab wound to the anterior cervical region presents to his six-month follow-up appointment. He states that despite surgery and physical rehabilitation, he still has difficulties with swallowing. An MRI is performed and reveals that all cervical musculature is intact. What muscle was likely pierced in order to damage the relevant nerves?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up

Anatomy, Head and Neck, Cervical Nerves - References

References

Lee JH,Cheng KL,Choi YJ,Baek JH, High-resolution Imaging of Neural Anatomy and Pathology of the Neck. Korean journal of radiology. 2017 Jan-Feb;     [PubMed]
Sakellariou VI,Badilas NK,Mazis GA,Stavropoulos NA,Kotoulas HK,Kyriakopoulos S,Tagkalegkas I,Sofianos IP, Brachial plexus injuries in adults: evaluation and diagnostic approach. ISRN orthopedics. 2014;     [PubMed]
Lee MW,McPhee RW,Stringer MD, An evidence-based approach to human dermatomes. Clinical anatomy (New York, N.Y.). 2008 Jul;     [PubMed]
Leijnse JN,D'Herde K, Revisiting the segmental organization of the human spinal cord. Journal of anatomy. 2016 Sep;     [PubMed]
Orebaugh SL,Williams BA, Brachial plexus anatomy: normal and variant. TheScientificWorldJournal. 2009 Apr 28;     [PubMed]
Mansukhani KA, Electrodiagnosis in traumatic brachial plexus injury. Annals of Indian Academy of Neurology. 2013 Jan;     [PubMed]
Kim JS,Ko JS,Bang S,Kim H,Lee SY, Cervical plexus block. Korean journal of anesthesiology. 2018 Aug;     [PubMed]
Costa MMB, NEURAL CONTROL OF SWALLOWING. Arquivos de gastroenterologia. 2018 Nov;     [PubMed]
Kubin L, Neural Control of the Upper Airway: Respiratory and State-Dependent Mechanisms. Comprehensive Physiology. 2016 Sep 15;     [PubMed]
Banneheka S, Anatomy of the ansa cervicalis: nerve fiber analysis. Anatomical science international. 2008 Jun;     [PubMed]
Iwanaga J,Fisahn C,Alonso F,DiLorenzo D,Grunert P,Kline MT,Watanabe K,Oskouian RJ,Spinner RJ,Tubbs RS, Microsurgical Anatomy of the Hypoglossal and C1 Nerves: Description of a Previously Undescribed Branch to the Atlanto-Occipital Joint. World neurosurgery. 2017 Apr;     [PubMed]
Zhang XY,Ma TT,Liu L,Yin NB,Zhao ZM, Anatomic study of the musculus longus capitis flap. Surgical and radiologic anatomy : SRA. 2017 Mar;     [PubMed]
Gavid M,Mayaud A,Timochenko A,Asanau A,Prades JM, Topographical and functional anatomy of trapezius muscle innervation by spinal accessory nerve and C2 to C4 nerves of cervical plexus. Surgical and radiologic anatomy : SRA. 2016 Oct;     [PubMed]
Kaplan PE, Electrodiagnostic confirmation of long thoracic nerve palsy. Journal of neurology, neurosurgery, and psychiatry. 1980 Jan;     [PubMed]
Mitsuoka K,Kikutani T,Sato I, Morphological relationship between the superior cervical ganglion and cervical nerves in Japanese cadaver donors. Brain and behavior. 2017 Feb;     [PubMed]
PICK J, The identification of sympathetic segments. Annals of surgery. 1957 Mar;     [PubMed]
Simoni P,Ghassemi M,Le VD,Boitsios G, Ultrasound of the Normal Brachial Plexus. Journal of the Belgian Society of Radiology. 2017 Dec 16;     [PubMed]
Lee HY,Chung IH,Sir WS,Kang HS,Lee HS,Ko JS,Lee MS,Park SS, Variations of the ventral rami of the brachial plexus. Journal of Korean medical science. 1992 Mar;     [PubMed]
Hughes DS,Keynes RJ,Tannahill D, Extensive molecular differences between anterior- and posterior-half-sclerotomes underlie somite polarity and spinal nerve segmentation. BMC developmental biology. 2009 May 22;     [PubMed]
Chakravorty BG, Arterial supply of the cervical spinal cord and its relation to the cervical myelopathy in spondylosis. Annals of the Royal College of Surgeons of England. 1969 Oct;     [PubMed]
Luo TD,Li Z, Brachial Plexus Injuries 2018 Jan;     [PubMed]
Magnus W,Mesfin FB, Cervical, Radiculopathy 2018 Jan;     [PubMed]
Polcaro L,Daly DT, Anatomy, Head and Neck, Brachial Plexus 2018 Jan;     [PubMed]
Bayot ML,Elzeftawy E, Anatomy, Shoulder and Upper Limb, Brachial Plexus 2018 Jan;     [PubMed]

Disclaimer

The intent of StatPearls is to provide practice questions and explanations to assist you in identifying and resolving knowledge deficits. These questions and explanations are not intended to be a source of the knowledge base of all of medicine, nor is it intended to be a board or certification review of Clinical Neurology-Medical Student. The authors or editors do not warrant the information is complete or accurate. The reader is encouraged to verify each answer and explanation in several references. All drug indications and dosages should be verified before administration.

StatPearls offers the most comprehensive database of free multiple-choice questions with explanations and short review chapters ever developed. This system helps physicians, medical students, dentists, nurses, pharmacists, and allied health professionals identify education deficits and learn new concepts. StatPearls is not a board or certification review system for Clinical Neurology-Medical Student, it is a learning system that you can use to help improve your knowledge base of medicine for life-long learning. StatPearls will help you identify your weaknesses so that when you are ready to study for a board or certification exam in Clinical Neurology-Medical Student, you will already be prepared.

Our content is updated continuously through a multi-step peer review process that will help you be prepared and review for a thorough knowledge of Clinical Neurology-Medical Student. When it is time for the Clinical Neurology-Medical Student board and certification exam, you will already be ready. Besides online study quizzes, we also publish our peer-reviewed content in eBooks and mobile Apps. We also offer inexpensive CME/CE, so our content can be used to attain education credits while you study Clinical Neurology-Medical Student.