C3 Nerve Root (C3)

Authors

Affiliations

Nate Yomogida, B.S., SPT

Doctor of Physical Therapy

B.S. in Kinesiology

Chloë Kerstein, B.S., SPT

Doctor of Physical Therapy

B.A. in Neuroscience

Figure 1: Hypoglossal nerve, cervical plexus, and their respective branches¹

Figure 2: Path of the Hypoglossal nerve¹

Figure 3: Nerve roots extending from the spinal cord¹

Motor Innervation

Muscle	Origin	Insertion	Innervation	Action
Levator scapulae	C1-C4 TP	Superior angle of Scapula	Dorsal scapular n. Cervical spinal nn. C3 - C4	Scapula: Elevation, Downward rotation Cervical: I/L sidebend
Longissimus capitis	T1-T3 TP C4-C7 TP & articular process	Mastoid process	Spinal nn. Posterior rami (lateral br.) C1 - C5	Bilateral: Head extension Unilateral: Ipsilateral head sidebend, Ipsilateral rotation
Longissimus cervicis	T1-T6 TP	C2-C5 TP	Spinal nn. Posterior rami (lateral br.) C1 - C5	Bilateral: Extends spine Unilateral: Ipsilateral spine sidebend
Longissimus thoracis	Sacrum Iliac crest Lumbar vertebrae SP Lower thoracic TP	2-12 Ribs Thoracic TP Lumbar TP	Spinal nn. Posterior rami (lateral br.) C1 - C5	Bilateral: Extends spine Unilateral: Ipsilateral spine sidebend
Lower trapezius	T5-T12 SP	Scapular spine	Accessory n. (CN XI) C3 - C4	Scapula: Retraction, Depression, Upward rotation, Stabilizes scapula on thorax
Middle scalene	C1-C2 TP Posterior tubercle of TP of C3-C7	1st Rib (posterior to groove for subclavian a.)	Anterior Rami C3 - C8	Mobile ribs: Elevates ribs during forced inspiration Fixed ribs (unilateral): I/L C/s sidebend (unilateral) Fixed ribs (bil): C/s flexion, Cervical lateral stabilization
Middle trapezius	Aponeurosis of T1-T4 SP	Acromion	Accessory n. (CN XI) C3 - C4	Scapula: Retraction
Splenius capitis	Nuchal lig. C7-T4 SP	Lateral third of nuchal line Mastoid process	Spinal nn. Posterior rami (lateral br.) C1 - C6	Bilateral: Head and neck extension Unilateral: I/L sidebend, I/L rotation
Splenius cervicis	T3-T7 SP	C1-C4 SP	Spinal nn. Posterior rami (lateral br.) C1 - C6	Bilateral: Head and neck extension Unilateral: I/L sidebend, I/L rotation
Sternocleidomastoid	Manubrium Medial third of Clavicle	Mastoid process Superior nuchal line	CN XI Accessory n. Cervical plexus C1 - C4	Unilateral: I/L cervical sidebend, C/L cervical rotation Bilateral: Head extension, Cervical Flexion, Assists in respiration, Prevents posterior translation during mastication SCJ stabilization
Upper trapezius	Occiput SP C1-C7	lateral 1/3 of Clavicle	Accessory n. (CN XI) C3 - C4	Scapula: Elevation, Upward rotatino Neck: I/L sidebend, C/L Rotation

Dermatome

Figure 4: Dermatomal cutaneous distribution¹

Figure 5: Dermatomal cutaneous distribution (Posterior)¹

Lesion

“Sensory disturbances occur on the lower occiput, the angle of the jaw, and the upper neck [28]. Paresis may occur in the scalene and levator scapulae muscles of the neck (including the infrahyoids, semispinalis capitis and cervicis, longissimus capitis and cervicis, intertransversarii, rotatores, multifidi), and in the trapezius (shoulder elevation), this last muscle being predominantly innervated by the spinal accessory nerve (cranial nerve XI). Diaphragmatic paresis may also result because the phrenic nerve receives some of its fibers from the C3 segment.”²

“Irritation of the C3 nerve root may cause a painful, burning, red ear (red ear syndrome) [15]. The increased ear temperature may be caused by antidromic release of vasodilator peptides. This red ear syndrome may also occur with temporomandibular joint dysfunction and with thalamic lesions [15].”²

References

1.

Gray H. Anatomy of the Human Body. 20th ed. (Lewis WH, ed.). Lea & Febiger; 1918. https://www.bartleby.com/107/

2.

Brazis PW, Masdeu JC, Biller J. Localization in Clinical Neurology. 8th ed. Wolters Kluwer Health; 2022.