The cervical nerves are spinal nerves that originate from the cervical segment of the spinal cord. These nerves carry motor and sensory information via efferent and afferent fibers to and from the central nervous system respectively. Although classified as a peripheral nerve, the motor cell body is located in the anterior horn of the spinal cord. There are eight pairs of cervical nerves, labeled C1 through C8, which originate from the spinal cord above their respective vertebrae, except for the C8 nerve, which originates from the C7 vertebra below. These nerves intertwine through the plexuses that give rise to the peripheral nerves, which maintain important motor functions in the head, neck, upper limbs, and diaphragm, as well as sensation in the head, neck, arms, and upper limbs in a dermatome pattern.
Structure and function
The cervical nerves emerge from the spinal cord in the form of roots or fila radcularia, smaller bundles of neurons that join together to form roots. For each spinal nerve, the anterior and posterior roots come together to form the entire nerve.Shortly after the spinal cord branches, the cervical nerves form the cervical and brachial plexuses. Note that input and output may vary from person to person, and therefore different sources may provide different descriptions.
The cervical plexus is formed by the ventral crest from C1 to C4. An anastomosis with the facial nerve, hypoglossal nerve, accessory spinal nerve, vagus nerve and sympathetic trunk is known. Located in front of the shoulder blades, but deep in the sternocleidomastoid,and gives rise to the motor and sensory branches:
The C1 spinal nerve gives rise to the genitourinary nerve and the thyroid nerve, which operate in the oropharynx. Anatomically, these nerves run close to the hypoglossal nerve (CN XII).
Ansa cervicalis (Latin for "neck handle") is a loop of nerves located superficial to the internal jugular vein, consisting of the C1 to C3 nerves. More specifically, one end of the loop, the upper root, comes from C1 (and possibly C2, depending on the literature), while the other, the lower root, comes from C2 and C3. From this structure arise the sternum, sternum and scapulohyoid nerves, as well as the upper and lower abdomen.All the muscles supplied by the branches of the cervical anus, including the thyroid gland, are hypohyoid muscles and therefore serve to compress the hyoid bone. This function is essential for correct speech and swallowing.
The roots C3, C4 and C5 contribute to the formation of the phrenic nerves. They are responsible for the motor and sensory supply of the diaphragm, as well as for the sympathetic output. The phrenic nerves extend anteriorly from the subclavian arteries, but posteriorly from the subclavian veins.
Apart from the cervical plexus, several muscles are directly innervated by the superior cervical roots:
C1 to C2: anterior/lateral rectus head
C1 to C3/4/5: Head length
C2/3 to C4: tabular form (sensory)
The cutaneous branches of the cervical plexus transmit sensory information from the skin of the neck, upper chest and scalp.These nerves originate from a common point on the back of the sternocleidomastoid muscle called Erb's point.There are several branches:
The inferior occipital nerve originates from C2 and supplies the skin on the neck and scalp behind and above the ear.
The greater auricular nerve C2 and C3 ascend in front of the ear and supply the skin over the parotid gland, the mastoid process, and the skin from the parotid gland to the mastoid process.
The C2 and C3 transverse cervical nerves project posteriorly and loop anteriorly to supply the skin of the anterior cervical region.
The supraclavicular nerves C3 and C4 descend from the posterior sternocleidomastoid muscle and provide sensory information from the skin over the clavicle and shoulder.
The ventral beak forming the cervical plexus, each of which receives a gray beak, is connected with the superior cervical ganglion by the sympathetic trunk.
The brachial plexus is formed from the ventral end of C5 to C8, as well as T1. The plexus projects laterally, in front of the first rib, but behind the clavicle, in the axillary region. The plexus is divided into many sections by numerous anastomoses from five nerve roots to three trunks, six branches, three cords and finally five branches.The end results are best described by where they exit the plexus rather than simply by their motor/sensory function, as many nerves carry both types of information:
From the roots C4 and C5 comes the dorsal scapulae nerve, which supplies the rhombuses and levator scapulae.
As previously mentioned, C5, along with C3 and C4, participates in the construction of the phrenic nerve that innervates the diaphragm.
The C5, C6, and C7 roots give rise to the long thoracic nerve, which is responsible for controlling the anterior dentate nerve.
From the upper trunk, C5 and C6 give rise to the subclavian and suprascapular nerves, which supply the subclavian muscle and the supraspinatus and supraspinatus muscles, respectively.
From the lateral bundle, C5, C6 and C7 supply the pectoralis major and minor muscles via the lateral and medial pectoral nerves, and the coracobrachial muscles, humerus and biceps brachii via the musculocutaneous nerve. The musculocutaneous nerve provides sensation to the skin on the lateral part of the forearm.
These three roots also form the lateral root of the median nerve, which controls most of the flexors of the forearm, with the exception of the flexor carpi ulnaris and medial flexors of the finger, the first and second psoas, and the teres. This nerve also provides sensation to the palm of the thumb, index finger, medial and lateral surfaces of the fourth finger.
The rear cable has five outputs:
From C5 and C6, the superior and inferior subscapularis nerves supply the upper and lower parts of the subscapularis muscle. The lower subscapular nerve also innervates the greater monster.
From C5 and C6, the axillary nerve also supplies the motor functions of the deltoid and minor longus, as well as the sensory layer of the skin, the upper lateral cutaneous nerve of the arm, and the skin of the lateral part of the arm. shoulder and shoulder. arm.
The thoracothoracic nerve originates from C6, C7 and C8 and innervates the latissimus dorsi.
Finally, the radial nerve, which originates from all five roots of the brachial plexus, is responsible for the motor innervation of the triceps brachii, biceps femoris, elbow, shoulder and all extensor muscles of the forearm. It also supplies the skin on the back of the arm, the back of the hand, and the membrane between the thumb and index finger.
The center wire also produces five outputs coming from C8 and T1:
The internal thoracic nerve supplies the pectoralis minor and part of the pectoralis major
Median root of the median nerve (see lateral root for details)
The medial cutaneous nerves in the arm and forearm are purely sensory and supply the medial skin of the arm and forearm respectively.
Finally, there is the ulnar nerve, which provides motor control to the flexor carpi ulnaris, flexor medialis, the two medial psoas muscles, the mediastinum and the subsphenoid muscles. It also provides sensation to the fifth digit, the hypotenoid eminence, and the middle half of the fourth finger.
For a more detailed discussion of brachial plexus structure, see the related StatPearls articles.
The spinal nerves come from the sclerotome, more precisely from the central area of the sclerotome in the anterior half. This part of the sclerotome is also responsible for the interneurium and perineurium of the spinal nerves. This origin contrasts with the posterior semi-sclerotome, which forms the bone and cartilage of the vertebral column. The posterior half also blocks the growth of neural crest cells and spinal nerve axons, leading to segmentation of the spinal nerve.
Blood and lymph supply
The spinal nerve roots are supplied with vessels from the root arteries. These arteries pass through the intervertebral openings with nerve roots. The first six vessels usually originate from the vertebral arteries or from the ascending carotid branch of the thyrocarotid trunk. In both cases, the spinal branches of these two vessels anastomose, so that if one of the sources is blocked, blood flow is maintained. The root arteries of the seventh and eighth segments are always formed by the branches of the costocervical trunk.
The cervical nerves innervate several muscle structures. The C1 spinal nerve gives rise to the genitourinary nerve and the thyroid nerve, which operate in the oropharynx. Anatomically, these nerves run close to the hypoglossal nerve (CN XII).Ansa cervicalis (Latin for "neck handle") is a loop of nerves located superficial to the internal jugular vein, consisting of the C1 to C3 nerves. More specifically, one end of the loop, the upper root, comes from C1 (and possibly C2, depending on the literature), while the other, the lower root, comes from C2 and C3. From this structure arise the sternum, sternum and scapulohyoid nerves, as well as the upper and lower abdomen.All the muscles supplied by the branches of the cervical anus, including the thyroid gland, are hypohyoid muscles and therefore serve to compress the hyoid bone. This function is essential for correct speech and swallowing.The roots C3, C4 and C5 contribute to the formation of the phrenic nerves. They are responsible for the motor and sensory supply of the diaphragm, as well as for the sympathetic output. The phrenic nerves extend anteriorly from the subclavian arteries, but posteriorly from the subclavian veins.Apart from the cervical plexus, several muscles are directly innervated by the superior cervical roots: C1 to C2: head straight ahead/to the side. C1 to C3/4/5: long head. C2/3 to C4: trapezius (sensory)
There are many varieties of cervical nerves and their derivatives that can occur in a patient. In particular, the cervical nerves that make up the cervical and brachial plexus vary greatly from person to person. In addition, the nerve endings originating from the cervical and brachial plexus may differ in their involvement and site of origin.
Cervical nerve pathology includes radiculopathy, which is most often caused by a spinal cord injury or herniated disc. This topic is discussed in detail in the StatPearls article referenced here.Surgery should be considered if the patient has neurological deficits and after MRI confirms gait, previous surgery and any comorbidities.
The most common pathology related to the cervical nerves, radiculopathy, is most often caused by a spinal cord injury or a herniated disc. This topic is discussed in detail in the StatPearls article referenced here.See the related StatPearls articles for more information on brachial plexus injuries as well as other pathologies related to the cervical nerve.
Review the questions
Posterior divisions, primary posterior divisions of the three upper cervical nerves, greater occipital nerve. Contributed by Gray's Anatomy Plates
cervical plexus. Includes ansa cervicalis. Contributed by: Henry Vandyke Carter [Public Domain]
Lee JH, Cheng KL, Choi YJ, Baek JH. High-resolution imaging of cervical nerve anatomy and pathology.Korean J Radiol.January-February 2017;18(1): 180-193.[Free PMC article: PMC5240499] [PubMed: 28096728]
Sakellariou VI, Badilas NK, Mazis GA, Stavropoulos NA, Kotoulas HK, Kyriakopoulos S, Tagkalegkas I, Sofianos IP. Urazy splotu ramiennego u dorosłych: ocena i sławt diagnostyczne.ISRN Orthop.2014;2014:726103.[Free PMC article: PMC4045362] [PubMed: 24967130]
Lee MW, McPhee RW, Stringer MD. An evidence-based approach to human dermatomes.Clin Anat.2008 July;21(5): 363-73.[PubMed: 18470936]
Cost MMB. NEURAL CONTROL OF EXTINGUISHING.Arq Gastroenterol.november 2018;55 Appendix 1(Supplement 1): 61-75.[PubMed: 30156597]
Banneheka S. Anatomy of the cervical anus: analysis of nerve fibers.Anat Sci Int.June 2008;83(2): 61-7.[PubMed: 18507614]
Iwanaga J, Fisahn C, Alonso F, DiLorenzo D, Grunert P, Kline MT, Watanabe K, Oskouian RJ, Spinner RJ, Tubbs RS. Microsurgical anatomy of the sublingual and C1 nerves: Description of a previously undescribed branch at the atlanto-occipital joint.Neurosurgery of the World.april 2017100:590-593.[PubMed: 28109859]
Zhang XY, Ma TT, Liu L, Yin NB, Zhao ZM. Anatomical study of the lobe of the long head muscle.Surg Radiol Res.marts 2017;39(3): 271-279.[PubMed: 27289229]
Gavid M, Mayaud A, Timochenko A, Asanau A, Prades JM. Topographic and functional anatomy of innervation of the trapezius muscle by the accessory spinal nerve and the C2 to C4 nerves of the cervical plexus.Surg Radiol Res.October 2016;38(8): 917-22.[PubMed: 26957148]
Mitsuoka K, Kikutani T, Sato I. Morphological relationship between the superior cervical ganglion and cervical nerves in Japanese cadaver donors.Behavior of the brain.February 2017?7(2): e00619.[Free PMC article: PMC5318372] [PubMed: 28239529]
[ PMC free article ] [ PubMed ] Lee HY, Chung IH, Sir WS, Kang HS, Lee HS, Ko JS, Lee MS, Park SS. Changes in the ventral end of plexus brachialis.J Korean Med Sci.1992 marts;7(1): 19-24.[Free PMC article: PMC3053802] [PubMed: 1418758]
Polcaro L, Charlick M, Daly DT.StatPearls [Internet].StatPearls Publishing; Treasure Island (FL): 22 Aug 2022. Anatomy, head and neck: brachial plexus. [PubMed: 30285368]
Bayot ML, Nassereddin A, Varacallo M.StatPearls [Internet].StatPearls Publishing; Treasure Island (FL): September 25, 2022. Anatomy, arm and upper limb, brachial plexus. [PubMed: 29763192]
Hughes DS, Keynes RJ, Tannahill D. Extensive molecular differences between anterior and posterior hemisclerotomes underlie somite polarization and spinal nerve segmentation.BMC Dev Biol.22 houses 2009;9:30.[Free PMC article: PMC2693541] [PubMed: 19463158]
Chakravorty BG. Arterial supply of the cervical spinal cord and its relationship to cervical myelopathy in spondylosis.Ann R Coll Surg Engl.October 1969;45(4): 232-51.[Free PMC article: PMC2387664] [PubMed: 4980920]
Magnus W, Viswanath O, Viswanathan VK, Mesfin FB.StatPearls [Internet].StatPearls Publishing; Treasure Island (FL): July 18, 2022. Cervical Radiculopathy. [PubMed: 28722858]
Luo TD, Levy ML, Li Z.StatPearls [Internet].StatPearls Publishing; Treasure Island (FL): 6. februar 2023 Plexus brachialis-skader. [PubMed: 29493930]
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