Autonomic Nervous System

Description

The autonomic nervous system (ANS) regulates involuntary body functions like heart rate, digestion, respiration, and glandular activity. It consists of two main divisions: the sympathetic (fight or flight) and parasympathetic (rest and digest) systems. The sympathetic system prepares the body for stress by increasing heart rate and dilating pupils, while the parasympathetic system conserves energy and promotes calming functions. The ANS operates via a two-neuron pathway (preganglionic and postganglionic) and uses neurotransmitters like acetylcholine and norepinephrine to control target organs.