logo Einloggen

Corpus: Ciliary ganglion

from Latin: cilium - cilium - eyelash

1. Definition

The ciliary ganglion is a small ganglion in the area of the eye socket (orbit). It belongs to the parasympathetic head ganglia.

2. Anatomy

2.1. Topography

The ciliary ganglion has a diameter of only 1-2 mm. It is located within the orbit about 2 cm behind the bulbus oculi (eyeball), positioned between the rectus lateralis muscle and the optic nerve.

2.2. Histology

The ciliary ganglion contains approximately 2,500 neurons. About twice as many parasympathetic fibers enter the ganglion as exit it, indicating that the ganglion is not merely a relay station but also a site of complex neuronal processing and interconnection.

2.3. Fibres

Sensory, sympathetic, and parasympathetic fibers pass through the ciliary ganglion, but only the parasympathetic fibers synapse within the ganglion. For the sensory and sympathetic fibers, the ganglion acts only as a transit station. All fibers emerging from the ganglion travel into the interior of the eye via the short ciliary nerves (nervi ciliares breves).

2.3.1. Parasympathetic fibres

The parasympathetic fibers of the ciliary ganglion originate from the accessory oculomotor nucleus (Edinger-Westphal nucleus). They travel with the oculomotor nerve (cranial nerve III) through the superior orbital fissure to the orbit, where they enter the ganglion as the motor root (radix oculomotoria). Here they synapse with postganglionic fibers, which then innervate the smooth muscles of the inner eye, including the ciliary muscle and the sphincter pupillae muscle.

2.3.2. Sympathetic fibres

The postganglionic sympathetic fibers of the ciliary ganglion originate from nerve cells in the superior cervical ganglion. They reach the ganglion via the internal carotid plexus and pass through without synapsing to innervate the dilator pupillae muscle, the orbital muscle, and the tarsal muscles.

2.3.3. Sensory fibres

Several somatosensory fibers from the nasociliary nerve (branch of cranial nerve V1) run through the ciliary ganglion as the long sensory root (radix longa ganglii ciliaris). They provide sensory innervation to the cornea and the conjunctiva.

3. Pathology

If the ciliary ganglion is damaged, the corneal reflex is lost, and the pupil can no longer respond to light stimuli.

Stichworte: Corpus, Head, Nerve

Empfehlung

Shop News Jobs CME Flexa Piccer
NEU: Log dich ein, um Artikel in persönlichen Favoriten-Listen zu speichern.
A
A
A

Teilen Was zeigt hierher Versionsgeschichte Artikel erstellen Discord
Miriam Dodegge
DocCheck Team
Natascha van den Höfel
DocCheck Team
Diese Funktion steht nur eingeloggten Abonnenten zur Verfügung
Letzter Edit:
24.06.2024, 16:24
33 Aufrufe
Nutzung: BY-NC-SA
Loading...
Loading...
Loading...
Loading...
Loading...
Loading...
Loading...