The greater splanchnic nerve is a major nerve that arises from the thoracic spinal cord, specifically from the T5 to T9 segments. It is part of the autonomic nervous system and primarily carries sympathetic fibers. This nerve plays a crucial role in transmitting signals to various abdominal organs, influencing functions such as digestion and blood flow. The greater splanchnic nerve innervates structures like the celiac ganglion, which is a cluster of nerve cells that relay signals to the stomach, liver, pancreas, and intestines. By regulating these organs, the nerve helps manage the body's response to stress and maintain homeostasis.