sympathetic trunk

The sympathetic trunk is a chain of nerve fibers running alongside your spine, part of the autonomic nervous system that controls involuntary body functions like heart rate and blood pressure. It acts as a communication highway between the brain and various organs, helping the body respond to stress or danger through "fight or flight" reactions. This trunk contains nerve fibers that project to different parts of the body, releasing chemicals like adrenaline to prepare you for action. Overall, it plays a crucial role in regulating involuntary physiological responses essential for survival.