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

== Smooth muscle mechanics ==

* '''Parasympathetic nerve terminals release acetylcholine (Ach)'''
** '''Which acts on muscarinic receptors'''
*** '''To induce detrusor contraction'''
**** '''By allowing calcium entry through Ca2+ channels'''
** Detrusor smooth muscle contraction sequence
**# Ca2+ binds to calmodulin, resulting in activation of calmodulin
**# Activated calmodulin activates the kinase enzyme (myosin light-chain kinase)
**# The kinase enzyme catalyzes phosphate transfer from adenosine triphosphate (ATP) to myosin, allowing myosin to interact with actin of the thin filaments.
**# '''Smooth muscle relaxes when intracellular Ca2+ levels decrease'''
* Although calcium serves the same triggering role in all muscle types, '''the''' '''contractile response in''' '''smooth muscle''' '''is slower and longer lasting''' than that of skeletal and cardiac muscle due to different mechanism of activation
* '''Interstitial cells or myofibroblasts have been proposed for a pacemaking role in spontaneous activity of the bladder'''