Nerve
Cervical plexus
Upper cervical network for neck sensation and movement
High-yield
Four cutaneous branches emerge near the middle of sternocleidomastoid’s posterior border: lesser occipital, great auricular, transverse cervical and supraclavicular nerves.
Overview
The anterior rami of C1–C4 join beneath sternocleidomastoid to form the cervical plexus. Its branches supply neck muscles and skin over parts of the head, neck and shoulder. The phrenic nerve receives an additional C5 contribution on its route to the diaphragm.
Reference facts
- Origin
- Anterior rami of cervical spinal nerves C1–C4
- Root value
- Plexus C1–C4; usual branches: lesser occipital C2, great auricular C2–C3, transverse cervical C2–C3, supraclavicular C3–C4, ansa C1–C3; phrenic C3–C5
- Course
- Deep to sternocleidomastoid, along the levator scapulae and middle scalene region, associated with the prevertebral fascia
- Motor
- Segmental neck-muscle branches; ansa branches to strap muscles; C1 fibers accompanying XII to geniohyoid and thyrohyoid; phrenic supply to the diaphragm
- Sensory
- Skin behind the ear and over parts of the auricle, mandibular angle, anterior/lateral neck, upper chest and shoulder
Mnemonic
C3, C4 and C5 contribute to the phrenic nerve that powers the diaphragm.
Clinical correlation
Sensory input from the central diaphragm travels through the phrenic nerve. Shared cervical spinal levels help explain why irritation there can be felt near the shoulder, where supraclavicular nerves supply skin.
Frequently asked questions
What are the roots of the cervical plexus?
Plexus C1–C4; usual branches: lesser occipital C2, great auricular C2–C3, transverse cervical C2–C3, supraclavicular C3–C4, ansa C1–C3; phrenic C3–C5.
What muscles does the cervical plexus supply?
Segmental neck-muscle branches; ansa branches to strap muscles; C1 fibers accompanying XII to geniohyoid and thyrohyoid; phrenic supply to the diaphragm.
What is the sensory distribution of the cervical plexus?
The cervical plexus carries sensation from the skin behind the ear and over parts of the auricle, mandibular angle, anterior/lateral neck, upper chest and shoulder.
What is the course of the cervical plexus?
Deep to sternocleidomastoid, along the levator scapulae and middle scalene region, associated with the prevertebral fascia.