Peripheral nerves6 min read

Reading peripheral nerve territories

Why peripheral nerve fields and dermatomes describe the same skin in two different languages.

Two maps of one surface

A dermatome map follows spinal roots. A peripheral nerve map follows named nerves after the plexuses have redistributed those roots. Both are correct; they simply answer different questions.

For surface work the peripheral map is often the more practical of the two, because named nerves follow palpable paths.

Working with both

The SIRIAM index tags every formulation with both its root levels and its named nerve fields, so a practitioner can search from whichever map they think in.

Related formulations

In the atlas

Peripheral nerve layer

Educational reference material. Nothing in the Knowledge Center is medical advice, and no therapeutic effect is claimed or implied.

Knowledge graph

Related knowledge

Structures, formulations and documentation connected to this article.

Formulation

FormulationPlexus Brachialis DUOShoulder–arm concept following the brachial plexus surface projection.→FormulationPlexus Lumbalis DUOLumbar plexus concept covering the lower back and anterior thigh projection field.→

Peripheral nerve

Peripheral nerveGreater occipital nerveC2 (dorsal ramus) — Posterior scalp from the superior nuchal line toward the vertex.→Peripheral nerveLesser occipital nerveC2–C3 — Lateral occipital scalp and superior auricular surface.→Peripheral nerveThird occipital nerveC3 (dorsal ramus) — Suboccipital surface and upper cervical midline.→Peripheral nerveGreat auricular nerveC2–C3 — Angle of the mandible, parotid surface and lower auricle.→Peripheral nerveSupraclavicular nervesC3–C4 — Lower neck, clavicular line and upper pectoral surface.→Peripheral nerveSupraorbital nerveV1 — Forehead and anterior scalp above the orbital rim.→

Knowledge article

Knowledge articleDermatomes: the segmental map of the skinHow the body surface is organised into segmental bands, and why those bands are a useful design language.→Knowledge articleThe brachial plexusC5–T1: roots, trunks, divisions, cords and terminal branches.→Knowledge articleThe lumbar plexusL1–L4 within the psoas major, projecting onto the anterior thigh.→