<prompt> The site of action of local anaesthetic in epidural anesthesia isSpinal nerve rootSpinal cordEpidural neural tissueAnterior root of spinal nerve  <response>: Local anaesthetic in maximal blockade is believed to act in spinal nerve root. Mechanism of action of central neuraxial blockade. The mechanisms of spinal and epidural are believed to be the nerve roots. Blockade of neural transmission in the posterior nerve root fibers interrupt somatic and visceral sensation, whereas blockade of anterior nerve root fibers prevent efferent motor autonomic outflow. 