42. The splanchnic nerves A) innervate the adrenal medulla B) are part of the sympathetic system C) usually synapse at collateral ganglia D) all of the above E) B and C only Solution The answer is D. All of the above. The splanchnic nerves are paired visceral nerves (nerves that contribute to the innervation of internal organs). They carry fibres of the Autonomic Nervous System - most of them carry Sympathetic fibres except the Pelvic Splanchnic Nerves which carry the parasympathetic fibres. The greater thoracic splanchnic nerves provide the sympathetic innervation to the adrenal medulla, stimulating catecholamine release. These thoracic splanchnic nerves synapse in collateral ganglia as the CELIAC AND SUPERIOR MESENTERIC GANGLIA..