C6 spinal nerve

At a glance

Level system

C6 nerve (named for its spinal cord segment)

Where it leaves the canal

The C6 nerve exits between the C5 vertebra and the C6 vertebra, above the C6 vertebra.Betts et al. 2022, §13.4

Distance down the canal before it exits

15 mmMeasured on one model: the Visible Human male, imaged as a supine cadaver. Not a normal range; drawn root, schematic

ISNCSCI key sensory point

Thumb, dorsal surface, proximal phalanxRupp et al. 2021; Kirshblum et al. 2011

ISNCSCI key muscle

Wrist extensors: tested by asking the person to extend the wristRupp et al. 2021; Kirshblum et al. 2011

Roots, ganglia and nerves are drawn schematically from each segment to its exit; their paths are not traced from imaging.

What the sources say

“The same occurs for C3 to C7, but C8 emerges between the seventh cervical vertebra and the first thoracic vertebra.” Betts et al. 2022, §13.4

“All of the spinal nerves are combined sensory and motor axons that separate into two nerve roots.” Betts et al. 2022, §13.4

“The sensory axons enter the spinal cord as the dorsal nerve root.” Betts et al. 2022, §13.4

“The motor fibers, both somatic and autonomic, emerge as the ventral nerve root.” Betts et al. 2022, §13.4

Connections to the rest of the body

• Spinal nerves and plexuses

  Brachial plexus: the nerves of the arm

  Spinal nerves from the lower neck and first thoracic segment regroup in the brachial plexus and become the nerves of the arm.

  Betts et al. 2022, §13.4 · Show on the body

• Key muscles (ISNCSCI)

  C6: wrist extensors

  In the standard neurological examination after spinal cord injury (ISNCSCI), the strength of the wrist extensors is the key test of segment C6. The muscle also receives other segments; the key muscle is a convention for testing, not the whole supply.

  Rupp et al. 2021; Betts et al. 2022, §11.5 · Show on the body

• Key sensory points (ISNCSCI)

  Key sensory points: one patch of skin per segment

  The examination tests light touch and pinprick at one key point per segment on each side, from C2 behind the ear to S4–5 beside the anus. The points here were placed on this body by following the standard’s written descriptions from bony landmarks, so they are approximate.

  Rupp et al. 2021; Kirshblum et al. 2011 · Show on the body

Read more

• Dermatomes and myotomes

  The map from spinal segments to skin and muscle. How dermatomes and key muscles are used to find the level of a spinal cord injury in the standard examination.

• The dorsal root ganglion

  The swelling on each dorsal root that holds the cell bodies of the body's sensory neurons. Why those neurons have a single split process, and what surrounds them.