•
The bladder and pelvic
floor receive most of their innervations from the pudendal nerve, with 70%
coming from the S3 nerve root and 30% from S2 and possibly S4.
•
Sacral parasympathetic preganglionic fibers
in the pelvic nerve provide the major excitatory input to the bladder.
•
Fibers originating in
the thoracolumbar sympathetic pathways provide the inhibitory input.
•
Afferent pelvic
pathways are composed of small, myelinated A fibers and unmyelinated
C-fibers.
•
These pathways,
transmitting signals from the bladder mechanoreceptors, pelvic visceral organs,
and somatic pathways, provide signals for the voluntary control of micturition.
