Cervical plexus

The cervical plexus is a plexus of the anterior rami of the first four cervical spinal nerves which arise from C1 to C4 cervical segment in the neck. They are located laterally to the transverse processes between prevertebral muscles from the medial side and vertebral (m. scalenus, m. levator scapulae, m. splenius cervicis) from lateral side. There is anastomosis with accessory nerve, hypoglossal nerve and sympathetic trunk.

Cervical plexus
Dermatome distribution of the trigeminal nerve (Superficial cervical plexus visible in purple, at center bottom.)
Details
From	C1-C4
Identifiers
Latin	plexus cervicalis
MeSH	D002572
TA	A14.2.02.012
FMA	5904
Anatomical terms of neuroanatomy

It is located in the neck, deep to the sternocleidomastoid muscle. Nerves formed from the cervical plexus innervate the back of the head, as well as some neck muscles. The branches of the cervical plexus emerge from the posterior triangle at the nerve point, a point which lies midway on the posterior border of the sternocleidomastoid. Also from the posterior ramus of C2 greater occipital nerve arises

Branches

The cervical plexus has two types of branches: cutaneous and muscular.

• Cutaneous (4 branches):
  • Lesser occipital - innervates the skin and the scalp posterosuperior to the auricle (C2)
  • Great auricular nerve - innervates skin near concha auricle (outer ear) and external acoustic meatus (ear canal) (C2&C3)
  • Transverse cervical nerve - innervates anterior region of neck (C2 and C3)
  • Supraclavicular nerves - innervate the skin above and below the clavicle (C3 and C4) [1]
• Muscular
  • Ansa cervicalis (This is a loop formed from C1-C3 which supplies the four infrahyoid aka strap muscles), etc. (thyrohyoid (C1 only), sternothyroid, sternohyoid, omohyoid)
  • Phrenic (C3-C5 (primarily C4))-innervates diaphragm and the pericardium
  • Segmental branches (C1-C4)- innervates anterior and middle scalenes

Additionally there are two branches formed by the posterior roots of spinal nerves:

• Preauricular nerve (from the posterior roots of C2–C3)[2][3]
• Postauricular nerve (from the posterior roots of C3–C4)[3]

Diagram

Additional images

• 
  Plan of the cervical plexus.
• 
  The nerves of the scalp, face, and side of neck.
• 
  The right sympathetic chain and its connections with the thoracic, abdominal, and pelvic plexuses.
• 
  Side of neck, showing chief surface markings.

See also

• Cervical plexus block

References

1. Clinically Oriented Anatomy by Moore and Dally's
2. Robert Schwartzman (15 April 2008). Neurologic Examination. John Wiley & Sons. p. 58. ISBN 978-1-4051-7283-7.
3. R.J. Schwartzman (31 July 2006). Differential Diagnosis in Neurology. IOS Press. pp. 326–. ISBN 978-1-60750-179-4.

External links

• Anatomy figure: 25:03-02 at Human Anatomy Online, SUNY Downstate Medical Center - "Diagram of the cervical plexus"
• MedicalMnemonics.com: 268
• Diagram at msu.edu