T3 spinal nerve

Nervus spinalis T3

NervousNervesThoraxLeft and right

View left in 3D View right in 3D

What it is
The T3 spinal nerve leaves the spinal canal between T3 and T4. Its sensory (dorsal) and motor (ventral) roots meet just beyond the dorsal root ganglion; the short mixed nerve then splits into a small dorsal ramus for the back muscles and skin and a larger ventral ramus, which becomes the 3rd intercostal nerve.
Function
Carries motor fibres to the muscles of its segment (myotome) and sensation back from its strip of skin (dermatome): a band of skin across the upper chest.
Size
About 2-3 mm thick; the mixed nerve is only ~1 cm long before it divides
Clinical note
Shingles (herpes zoster) reactivates in a thoracic dorsal root ganglion more often than anywhere else, giving a painful blistering stripe along one dermatome.

Nearby nervous structures 1st intercostal nerve, 3rd intercostal nerve, 4th intercostal nerve, T1 spinal nerve, T2 spinal nerve, T4 spinal nerve, T5 spinal nerve, T6 dorsal root ganglion, T6 spinal nerve, T7 spinal nerve