Splanchnic nerve

Splanchnic Nerve

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Splanchnic nerves diagram

The Splanchnic Nerves are paired visceral nerves (nerves that contribute to the innervation of the internal organs), carrying fibers of the autonomic nervous system (both sympathetic and parasympathetic).

Anatomy

The splanchnic nerves arise from the vertebral column and pass through the diaphragm to reach the organs of the abdomen. There are three main splanchnic nerves: the greater, lesser, and least (or lowest) splanchnic nerves. They carry sympathetic fibers to the celiac ganglia and abdominal aortic plexus.

Greater Splanchnic Nerve

The Greater splanchnic nerve, the largest of the splanchnic nerves, arises from the thoracic spinal cord, typically spanning the 5th-9th thoracic vertebrae.

Lesser Splanchnic Nerve

The Lesser splanchnic nerve usually arises from the 10th and 11th thoracic vertebrae and carries sympathetic fibers to the aorticorenal ganglion.

Least Splanchnic Nerve

The Least splanchnic nerve, also known as the lowest splanchnic nerve, arises from the last thoracic vertebra and carries sympathetic fibers to the renal plexus.

Function

The splanchnic nerves are responsible for innervating the viscera, carrying sympathetic fibers. They play a crucial role in the regulation of gastrointestinal functions, such as motility and secretion, and are involved in the body's response to stress and emergency situations, often referred to as the "fight or flight" response.

Clinical Significance

Understanding the anatomy and function of the splanchnic nerves is crucial in several clinical scenarios, including splanchnic nerve block procedures to alleviate chronic abdominal pain, and in the surgical management of conditions such as portal hypertension.

See Also

• Autonomic nervous system
• Sympathetic ganglia
• Celiac plexus