Crossword Puzzle sympathetic & parasympathetic Online version differences between sympathetic & parasympathetic divisions by Chloe Griffith 1 releases norepinephrine 2 release ACh 3 what neurons use to communicate with each other - or their effector organs across a synapse 4 reduce blood flow to areas 5 released from postganglionic fibers in the sympathetic nervous system; it's what crosses that final synapse and creates a response in the effector 6 peripheral & central nervous system use to communicate 7 release norepinephrine as a hormone 8 feed skeletal muscles 9 regulate sleep cycle, maintain water, etc. 10 neurotransmitters & hormones 4 8 2 5 3 7 6 10 9