The autonomic nervous system is the part of the nervous system that controls automatic body functions—those we don’t consciously direct, like heartbeat, breathing, digestion, or sweating.
It has two main branches:
Sympathetic nervous system – activates the “fight-or-flight” response during stress (faster heart rate, increased blood pressure, release of adrenaline).
Parasympathetic nervous system – promotes “rest and digest,” calming the body and restoring balance after stress.
The ANS keeps our body in homeostasis, constantly adjusting internal processes to maintain stability. It also plays a significant role in how we physically experience emotions—for instance, a racing heart when we are anxious or a relaxed state when we are calm.