2. Autonomic Nervous System
It Controls involuntary bodily functions like heart rate, breathing, digestion, and blood pressure, operating automatically without conscious thought to maintain homeostasis (internal balance). It's part of the peripheral nervous system, divided into the sympathetic (fight-or-flight) system, which prepares the body for action, and the parasympathetic (rest-and-digest) system, which conserves energy, with both working in balance