Sensory root of ciliary ganglion
Encyclopedia
Sensory fibers from the eyeball (the cornea
, iris
and ciliary body
) run posteriorly through the short ciliary nerves
and pass through the ciliary ganglion
without forming synapses. They leave the ciliary ganglion in the sensory root of ciliary ganglion, which joins the nasociliary nerve
.
The nasociliary nerve is a branch of the ophthalmic nerve
, one of the three branches (V1) of the trigeminal nerve
. The trigeminal nerve is the main sensory nerve of the face.
Sensory fibers from other parts of the eye run through the long ciliary nerves
and other peripheral branches of the ophthalmic nerve
.
Cornea
The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Together with the lens, the cornea refracts light, with the cornea accounting for approximately two-thirds of the eye's total optical power. In humans, the refractive power of the cornea is...
, iris
Iris (anatomy)
The iris is a thin, circular structure in the eye, responsible for controlling the diameter and size of the pupils and thus the amount of light reaching the retina. "Eye color" is the color of the iris, which can be green, blue, or brown. In some cases it can be hazel , grey, violet, or even pink...
and ciliary body
Ciliary body
The ciliary body is the circumferential tissue inside the eye composed of the ciliary muscle and ciliary processes. It is triangular in horizontal section and is coated by a double layer, the ciliary epithelium. This epithelium produces the aqueous humor. The inner layer is transparent and covers...
) run posteriorly through the short ciliary nerves
Short ciliary nerves
The branches of the ciliary ganglion are the short ciliary nerves.These are delicate filaments, from six to ten in number, which arise from the forepart of the ganglion in two bundles connected with its superior and inferior angles; the lower bundle is the larger.They run forward with the ciliary...
and pass through the ciliary ganglion
Ciliary ganglion
The ciliary ganglion is a parasympathetic ganglion located in the posterior orbit. It measures 1–2 millimeters in diameter and contains approximately 2,500 neurons. Preganglionic axons from the Edinger-Westphal nucleus travel along the oculomotor nerve and form synapses with these cells...
without forming synapses. They leave the ciliary ganglion in the sensory root of ciliary ganglion, which joins the nasociliary nerve
Nasociliary nerve
The nasociliary nerve is a branch of the ophthalmic nerve. It is intermediate in size between the two other main branches of the ophthalmic nerve, the frontal nerve and the lacrimal nerve, and is more deeply placed.-Path:...
.
The nasociliary nerve is a branch of the ophthalmic nerve
Ophthalmic nerve
The ophthalmic nerve is one of the three branches of the trigeminal nerve, the fifth cranial nerve. The ophthalmic nerve carries only sensory fibers.-Branches:*Nasociliary nerve**sensory root of ciliary ganglion**posterior ethmoidal nerve...
, one of the three branches (V1) of the trigeminal nerve
Trigeminal nerve
The trigeminal nerve contains both sensory and motor fibres. It is responsible for sensation in the face and certain motor functions such as biting, chewing, and swallowing. Sensory information from the face and body is processed by parallel pathways in the central nervous system...
. The trigeminal nerve is the main sensory nerve of the face.
Sensory fibers from other parts of the eye run through the long ciliary nerves
Long ciliary nerves
The long ciliary nerves, two or three in number, are given off from the nasociliary, as it crosses the optic nerve.They accompany the short ciliary nerves from the ciliary ganglion, pierce the posterior part of the sclera, and running forward between it and the choroid, are distributed to the iris...
and other peripheral branches of the ophthalmic nerve
Ophthalmic nerve
The ophthalmic nerve is one of the three branches of the trigeminal nerve, the fifth cranial nerve. The ophthalmic nerve carries only sensory fibers.-Branches:*Nasociliary nerve**sensory root of ciliary ganglion**posterior ethmoidal nerve...
.
Variability
The exact distribution of sensory fibers, like the distribution of sympathetic fibers, is anatomically variable. There are alternate pathways to the eye for both sympathetic and sensory fibers, and the precise anatomy varies from person to person. Since the result is the same regardless of how the fibers reach the eye, the presence of sympathetic and sensory fibers in the ciliary ganglion (the contributions of the “sensory” and “sympathetic” roots) is of no functional significance.External links
- http://anatomy.med.umich.edu/modules/head_autonomics_module/autonomics_05.html