A dermatome is an area of skin that is mainly supplied by a single spinal nerve.
A similar area innervated by peripheral nerves is called a peripheral nerve field.
Dermatomes are useful in locating the site of damage to the spine.
Important dermatomes and anatomical landmarks
* C2 – posterior half of the skull cap
* C3 – area correlating to a high turtle neck shirt
* C4 – area correlating to a low-collar shirt
* C6 – (radial nerve) 1st digit (thumb)
* C7 – (median nerve) 2nd and 3rd digit
* C8 – (ulnar nerve) 4th and 5th digit, also the funny bone
* T4 – nipples.
* T5 – Inframammary fold.
* T6/T7 – xiphoid process.
* T10 – umbilicus (important for early appendicitis pain)
* T12 – pubic bone area.
* L1 – inguinal ligament
* L4 – includes the knee caps
* S2/S3 – genitalia