The least splanchnic nerve is a small nerve that arises from the thoracic spinal cord, specifically from the T12 segment. It is part of the autonomic nervous system and primarily carries sympathetic fibers. This nerve plays a role in innervating the abdominal organs, particularly the kidneys and the adrenal glands, helping to regulate functions such as blood flow and hormone release. This nerve is one of several splanchnic nerves, which include the greater and lesser splanchnic nerves. Together, these nerves contribute to the sympathetic innervation of the abdominal cavity and its organs, facilitating the body's response to stress and maintaining homeostasis.