Cystic plexus is the derivation of hepatic plexus, which is the largest offshoot from celiac plexus.
Formed by the branches from celiac plexus, right and left vagi and right phrenic nerve. Parasympathetic nerves are motor to musculature of gall bladder and bile ducts, but inhibitory to the sphincters. Sympathetic nerves derived from thoracic seven to nine segments are vasomotor and motor to sphincters.
It supplies the gall bladder, common hepatic duct, cystic duct and upper part of bile duct. The lower part of bile duct is supplied by nerve plexus around superior pancreaticoduodenal artey.
References
Cystic plexus Wikipedia(Text) CC BY-SA