general visceral efferent fibre

General visceral efferent fibers are a type of motor nerve fiber that originates from cell bodies within the spinal cord. These fibers exit the spinal cord at specific thoracic and upper lumbar levels (T₁–L₂) or sacral levels (S₂–S₄).1

Fibers from the T₁–L₂ levels travel to the sympathetic trunk, where they may synapse within a ganglion, move up or down the trunk, or proceed to ganglia closer to their target organs. Fibers from the S₂–S₄ levels leave the spinal cord as the pelvic nerve and go to terminal ganglia within the target organs.1

Postganglionic fibers from these ganglia then distribute to visceral structures. These fibers are part of the autonomic nervous system and control internal organs, smooth muscle, and cardiac muscle. Unlike the sympathetic nervous system, the parasympathetic system, which also uses general visceral efferent fibers, is not crucial for immediate survival but plays a vital role in modulating organ function.123