File:Dermatomes.png: Difference between revisions

Skin Dermatomes

Image shows the approximate spinal cord nerve segmental innervation of the skin regions.

Spinal Nerve Pattern

• Cervical spinal nerve 2 (C2)) - At least one cm lateral to the occipital protuberance at the base of the skull. Alternately, a point at least 3 cm behind the ear.
• Cervical spinal nerve 3 (C3) - In the supraclavicular fossa, at the mid-clavicular line.
• Cervical spinal nerve 4 (C4) - Over the acromioclavicular joint.
• Cervical spinal nerve 5 (C5) - On the lateral (radial) side of the antecubital fossa, just proximally to the elbow.
• Cervical spinal nerve 6 (C6) - On the dorsal surface of the Proximal phalanges (proximal phalanx of the thumb).
• Cervical spinal nerve 7 (C7) - On the dorsal surface of the Proximal phalanges (proximal phalanx of the middle finger).
• Cervical spinal nerve 8 (C8) - On the dorsal surface of the proximal phalanx of the little finger.
• Thoracic spinal nerve 1 (T1) - On the medial (ulnar) side of the antecubital fossa, just proximally to the medial epicondyle of the humerus.
• Thoracic spinal nerve 2 (T2) - At the apex of the axilla.
• Thoracic spinal nerve 3 (T3) - Line-line intersection (Intersection of the mid-clavicular line and the third intercostal space
• Thoracic spinal nerve 4 (T4) - Intersection of the midclavicular line and the fourth intercostal space, located at the level of the nipples.
• Thoracic spinal nerve 5 (T5) - Intersection of the midclavicular line and the fifth intercostal space, horizontally located midway between the level of the nipples and the level of the xiphoid process.
• Thoracic spinal nerve 6 (T6) - Intersection of the midclavicular line and the horizonal level of the xiphoid process.
• Thoracic spinal nerve 7 (T7) - Intersection of the midclavicular line and the horizontal level at one quarter the distance between the level of the xiphoid process and the level of the umbilicus.
• Thoracic spinal nerve 8 (T8) - Intersection of the midclavicular line and the horizontal level at one half the distance between the level of the xiphoid process and the level of the umbilicus.
• Thoracic spinal nerve 9 (T9) - Intersection of the midclavicular line and the horizontal level at three quarters of the distance between the level of the xiphoid process and the level of the umbilicus.
• Thoracic spinal nerve 10 (T10) - Intersection of the midclavicular line, at the horizontal level of the umbilicus.
• Thoracic spinal nerve 11 (T11) - Intersection of the midclavicular line, at the horizontal level midway between the level of the umbilicus and the inguinal ligament.
• Thoracic spinal nerve 12 (T12) - Intersection of the midclavicular line and the midpoint of the inguinal ligament.
• Lumbar spinal nerve 1 (L1) - Midway between the key sensory points for T12 and L2.
• Lumbar spinal nerve 2 (L2) - On the anterior medial thigh, at the midpoint of a line connecting the midpoint of the inguinal ligament and the medial epicondyle of the femur.
• Lumbar spinal nerve 3 (L3) - At the medial epicondyle of the femur.
• Lumbar spinal nerve 4 (L4) - Over the medial malleolus.
• Lumbar spinal nerve 5 (L5) - On the foot dorsum dorsum of the foot at the third metatarsophalangeal joint.
• Sacral spinal nerve 1 (S1) - On the lateral aspect of the calcaneus.
• Sacral spinal nerve 2 (S2) - At the midpoint of the popliteal fossa.
• Sacral spinal nerve 3 (S3) - Over the tuberosity of the ischium or infragluteal fold.
• Sacral spinal nerve 4 (S4) - and Sacral spinal nerve 5 (S5) - In the perianal area, less than one cm lateral to the mucocutaneous zone.

Source: http://en.wikipedia.org/wiki/File:Dermatoms.svg