Dorothy was walking through the woods arm in arm with two fr…

Dorothy was walking through the woods arm in arm with two friends and her little dog, when all of the sudden a lion, a tiger and a bear jumped out of the bushes at them.  Dorothy jumped up and screamed “Lions and Tigers and Bears!  Oh My!”  She started running.  Her legs were churning and her heart was pumping.  When she finally stopped, she was completely out of breath.  After several minutes, her heart rate returned to normal, her breathing slowed and she started to calm down.  She turned to her little dog and whispered “Oh Toto!  There’s no place like home.” What portion of Dorothy’s PNS caused her legs to “churn”?