Why sympathetic trunk is called trunk?

The sympathetic trunk is called a "trunk" because it serves as a major conduit for sympathetic nerve fibers that run along each side of the vertebral column, resembling a tree trunk from which branches extend. It acts as a central pathway for the sympathetic nervous system, facilitating communication between the spinal cord and peripheral targets. This anatomical structure is crucial for coordinating the body's involuntary responses to stress and maintaining homeostasis.