The sympathetic trunk is a part of the autonomic nervous system, specifically the sympathetic division. It consists of a chain of interconnected ganglia located alongside the vertebral column. These ganglia are responsible for transmitting signals that prepare the body for "fight or flight" responses, regulating functions like heart rate and blood pressure. The sympathetic trunk extends from the base of the skull to the coccyx, with ganglia at various levels corresponding to different spinal nerves. It plays a crucial role in the body's stress response and interacts with other structures, such as the parasympathetic nervous system and spinal cord, to maintain homeostasis.