Editing Bladder (section)

== Innervation ==

=== Efferent ===
* '''The bladder wall is richly supplied with parasympathetic cholinergic nerve endings.'''
* '''Sparse sympathetic innervation of the bladder has been proposed to mediate detrusor relaxation''' but probably lacks functional significance
* Nitric oxide synthase–containing neurons have been identified in the detrusor, particularly at the bladder neck, where they facilitate relaxation during micturition.
* '''In males, the internal sphincter is richly innervated by adrenergic fibers, which act on α1-adrenergic receptors, and when stimulated, produce closure of the bladder neck.'''
** '''The internal sphincter is responsible for continence at the level of the bladder neck'''.
*** Perfect continence can be maintained in men in whom the striated urethral sphincter is destroyed, demonstrating the efficacy of this sphincter.
*** '''Damage to the sympathetic nerves leading to the bladder, as a result of diabetes mellitus or retroperitoneal lymph node dissection for testis cancer, can cause retrograde ejaculation'''.
* '''The female bladder neck has little adrenergic innervation.'''
* '''The trigonal muscle is innervated by adrenergic and nitric oxide synthase–containing neurons. Like the bladder neck, it relaxes during micturition.'''

=== Afferent ===
* '''Both sympathetic (via the hypogastric nerves) and parasympathetic nerves travel via the lateral and posterior pedicles to reach cell bodies in the dorsal root ganglia located at thoracolumbar and sacral levels, respectively.'''
** '''In females, the parasympathetics travel via the cardial ligament.''' As a consequence, presacral neurectomy (division of the hypogastric nerves) is ineffective in relieving bladder pain.