Anatomy and Function of the Cervical Sympathetic Chain

Overview

The cervical sympathetic chain is an essential component of the autonomic nervous system, responsible for regulating involuntary functions such as pupil dilation, sweating, and blood vessel constriction. This chain extends from the base of the skull to the thoracic region and consists of interconnected sympathetic ganglia.

Extent of the Cervical Sympathetic Chain

The cervical sympathetic chain extends from the superior cervical ganglion at the skull base down to the stellate ganglion, located at the junction of the cervical and thoracic regions.

Anatomy of the Cervical Sympathetic Chain

• Superior Cervical Ganglion: Located at the level of the C2-C3 vertebrae, this ganglion is responsible for supplying sympathetic fibers to the head.
• Middle Cervical Ganglion: Found around the level of the C6 vertebra, contributing to cardiac and thyroid innervation.
• Inferior Cervical (Stellate) Ganglion: A fusion of the inferior cervical and first thoracic ganglia, influencing cardiac and vascular responses.

Functions

• Regulates blood flow to the head and neck.
• Controls pupil dilation via sympathetic innervation.
• Influences heart rate and respiratory function.
• Modulates sweating and thermoregulation.

Clinical Significance

Disruptions in the cervical sympathetic chain can lead to conditions such as Horner’s syndrome, characterized by ptosis, miosis, and anhidrosis. Surgical procedures near the cervical region should be conducted carefully to avoid compromising sympathetic function.