Editing Functional: Neural Control of Storage and Voiding (section)

== Reflex circuitry controlling continence and micturition ==

=== Storage reflexes ===
* See [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2897743/figure/F5/ Figure 5a] for storage reflex
* '''Also known as “guarding reflex”, “spinal reflex”, “spinal reflex pathway”, “bladder sympathetic reflex”'''
* '''<span style="color:#ff0000">Promotes continence</span>'''
** '''During the storage of urine, distention of the bladder produces low-level bladder afferent firing via Aδ-myelinated nerves'''
** '''There is a gradual increase in proximal urethral pressure during bladder filling''', contributed to at least by the striated sphincteric element and perhaps by the smooth sphincteric element as well.
** '''<span style="color:#ff0000">Afferent stimulation, in turn, results in efferent(2):</span>'''
**# '''<span style="color:#ff0000">Sympathetic outflow resulting in</span>'''
**## '''<span style="color:#ff0000">Excitation (contraction) of bladder base and urethra</span>'''
**## '''<span style="color:#ff0000">Inhibition (relaxation) of bladder</span>'''
**# '''<span style="color:#ff0000">Pudendal outflow to the EUS</span>'''
**#* The increase in urethral pressure seen during the filling/storage phase of micturition can be correlated with an increase in efferent pudendal nerve impulse frequency and gradual increase in striated sphincter activity.
**# '''<span style="color:#ff0000">Note that the parasympathetic outflow is inactive'''

=== Voiding reflexes ===
* See [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2897743/figure/F5/ Figure 5b] for voiding reflex
* '''Also known as “micturition reflex”, “spinobulbospinal reflex”'''
* '''<span style="color:#ff0000">Upon initiation of micturition, there is high-level afferent activity signaling wall tension, which activates the PMC</span>'''
* '''<span style="color:#ff0000">In response, the PMC:</span>'''
*# '''<span style="color:#ff0000">Inhibits the guarding reflex, thereby reducing sympathetic</span>''' (resulting in inhibition (relaxation) of bladder base and urethra and excitation (contraction) of the detrusor muscle) '''<span style="color:#ff0000">and pudendal</span>''' (resulting in inhibition (relaxation) of EUS) '''<span style="color:#ff0000">nerve outflow</span>'''
*# '''<span style="color:#ff0000">Stimulates parasympathetic outflow resulting in (2):</span>'''
*## '''<span style="color:#ff0000">Excitation (contraction) of bladder</span>'''
*## '''<span style="color:#ff0000">Inhibition (relaxation) of [urethra]/</span>'''internal sphincter smooth muscle
* '''Maintenance of the voiding reflex is through ascending afferent input from the spinal cord, which may pass through the periaqueductal gray matter (PAG) before reaching the PMC'''
* Described as a spinobulbospinal reflex because of the ascending signal from afferent pelvic nerve stimulation, which passes through the periaqueductal gray matter in the bulbar region of the brain before reaching the pontine micturition center and descending to elicit parasympathetic contraction of the detrusor, and somatic relaxation via the pudendal nerve