What are the differences between Parasympathetic nervous system and sympathetic nervous system

The parasympathetic nervous system responds when the body is relaxed and at rest while sympathetic nervous system is responsible for response to emergency situation.

Explanation:

The sympathetic nervous system is called fight or flight division while the parasympathetic nervous system is the rest and digest division. The pre-ganglionic neurons of sympathetic nervous system arises from lumbar and thoracic regions of spinal chord while the preganglionic neurons of parasympathetic nervous system arises from the brain and sacral region of the spinal cord. The sympathetic nervous system decreases the activity of digestive system while the parasympathetic nervous system increases the activity of digestive system. Sympathetic nervous system dilates bronchioles while parasympathetic nervous system constricts bronchioles. Sympathetic nervous system increases blood pressure while parasympathetic nervous system usually do not effect blood pressure. Sympathetic nervous system increases heart rate while parasympathetic nervous system decreases heart rate.