Nerve
Superior cervical ganglion
A major sympathetic relay for the head
High-yield
The ocular sympathetic pathway relays here before following the internal carotid toward the orbit. Many facial sweating fibers instead follow external-carotid routes, so the location of a lesion influences whether Horner syndrome includes extensive facial anhidrosis.
Overview
The uppermost cervical sympathetic ganglion usually lies near C2–C3, deep to the carotid sheath and close to prevertebral muscles. Preganglionic fibers ascend from upper thoracic spinal levels to relay here. Postganglionic axons follow carotid arterial plexuses and other branches toward the head, neck and cardiac plexus.
Reference facts
- Origin
- Preganglionic sympathetic neurons in the upper thoracic cord send axons upward through the sympathetic trunk.
- Root value
- Upper thoracic preganglionic input; the ocular pathway is associated with the lower cervical–upper thoracic ciliospinal region. C2–C3 refers to the ganglion's neck position, not its spinal root of origin.
- Course
- Usually around C2–C3 near longus capitis/longus colli and the carotid sheath. Axons leave through internal/external carotid plexuses and other cervical branches.
- Motor
- Sympathetic supply to pupillary dilator and superior tarsal muscle, head-and-neck vessels and sweat glands, with a superior cervical cardiac contribution.
- Sensory
- Its relay neurons are sympathetic efferents. Sensory fibers traveling through associated autonomic pathways do not acquire their cell bodies or synapse here.
Clinical correlation
Interruption anywhere along the oculosympathetic pathway can cause a smaller pupil and partial upper-lid droop. Sweating loss varies; lesions along the internal carotid after the ganglion may spare much of the face. These signs localize a pathway, not one inevitable cause.
Frequently asked questions
What are the roots of the superior cervical ganglion?
Upper thoracic preganglionic input; the ocular pathway is associated with the lower cervical–upper thoracic ciliospinal region. C2–C3 refers to the ganglion's neck position, not its spinal root of origin.
What muscles does the superior cervical ganglion supply?
Sympathetic supply to pupillary dilator and superior tarsal muscle, head-and-neck vessels and sweat glands, with a superior cervical cardiac contribution.
What is the sensory distribution of the superior cervical ganglion?
Its relay neurons are sympathetic efferents. Sensory fibers traveling through associated autonomic pathways do not acquire their cell bodies or synapse here.
What is the course of the superior cervical ganglion?
Usually around C2–C3 near longus capitis/longus colli and the carotid sheath. Axons leave through internal/external carotid plexuses and other cervical branches.