S5 spinal nerve

Nervus spinalis S5

NervousNervesPelvisLeft and right

View left in 3D View right in 3D

What it is
The S5 spinal nerve leaves the spinal canal between the sacral hiatus and the coccyx. 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 joins the small coccygeal plexus.
Function
Carries motor fibres to the muscles of its segment (myotome) and sensation back from its strip of skin (dermatome): the skin immediately around the anus.
Size
About 1 mm thick; the mixed nerve is only ~1 cm long before it divides
Clinical note
A tiny nerve that joins S4 and the coccygeal nerve in the coccygeal plexus.

Nearby nervous structures Co1 spinal nerve, Ganglion impar, Pudendal nerve, S1 spinal nerve, S2 spinal nerve, S3 spinal nerve, S4 spinal nerve, Superior and inferior hypogastric plexuses