abnormal sympathetic system morphology abnormal splanchnic nerve morphology MP:0008318 MPheno.ontology abnormal abdominopelvic splanchnic nerve morphology abnormal cardiopulmonary splanchnic nerve morphology abnormal pelvic splanchnic nerve morphology any structural anomaly of the major nerves supplying sympathetic innervation to the abdomen, including the greater, lesser, and lowest (or smallest) splanchnic nerves that are formed by preganglionic fibers from the spinal cord which pass through the paravertebral ganglia and then to the celiac ganglia and plexuses and the lumbar splanchnic nerves carry fibers which pass through the lumbar paravertebral ganglia to the mesenteric and hypogastric ganglia