Cavernous plexus

Cavernous plexus

Diagram of the autonomic nervous system, showing the cavernous plexus.
Latin	plexus cavernosus
System	Nervous system

The cavernous plexus is a network of nerves located within the cavernous sinus, a cavity at the base of the skull that houses important cranial nerves and the internal carotid artery. This plexus is part of the autonomic nervous system and plays a crucial role in the innervation of the eye and surrounding structures.

Anatomy

The cavernous plexus is situated on the lateral side of the sella turcica, a saddle-shaped depression in the sphenoid bone that holds the pituitary gland. It is closely associated with the cavernous sinus, a venous channel that drains blood from the brain back to the heart.

Components

The cavernous plexus contains both sympathetic and parasympathetic fibers:

• Sympathetic fibers: These originate from the superior cervical ganglion and travel along the internal carotid artery to reach the plexus. They are responsible for the dilation of the pupil (mydriasis) and the elevation of the eyelid (via the superior tarsal muscle).

• Parasympathetic fibers: These are derived from the oculomotor nerve (CN III) and are involved in the constriction of the pupil (miosis) and accommodation of the lens for near vision.

Function

The primary function of the cavernous plexus is to provide autonomic innervation to the structures within the orbit. It regulates the size of the pupil, the position of the eyelid, and the focus of the lens, thereby playing a vital role in vision.

Clinical Significance

Disorders affecting the cavernous plexus can lead to a variety of symptoms, including:

• Horner's syndrome: Characterized by ptosis (drooping of the eyelid), miosis (constricted pupil), and anhidrosis (lack of sweating) on the affected side of the face. This occurs due to disruption of sympathetic fibers.

• Cavernous sinus syndrome: A condition that can result from infection, thrombosis, or tumor, leading to dysfunction of the cranial nerves passing through the cavernous sinus, including the oculomotor nerve, trochlear nerve, and abducens nerve.

Also see

• Cavernous sinus
• Autonomic nervous system
• Cranial nerves
• Horner's syndrome