The posterior ethmoidal nerve is a

nerve A nerve is an enclosed, cable-like bundle of nerve fibers (called axons) in the peripheral nervous system. A nerve transmits electrical impulses. It is the basic unit of the peripheral nervous system. A nerve provides a common pathway for the ...

of the orbit around the eye. It is a branch of the

nasociliary nerve The nasociliary nerve is a branch of the ophthalmic nerve, itself a branch of the trigeminal nerve (CN V). It is intermediate in size between the other two branches of the ophthalmic nerve, the frontal nerve and lacrimal nerve. Structure The na ...

from the ophthalmic nerve (CN V₁). It supplies sensation to the sphenoid sinus, the ethmoid sinus, and part of the

dura mater In neuroanatomy, dura mater is a thick membrane made of dense irregular connective tissue that surrounds the brain and spinal cord. It is the outermost of the three layers of membrane called the meninges that protect the central nervous system. ...

in the

anterior cranial fossa The anterior cranial fossa is a depression in the floor of the cranial base which houses the projecting frontal lobes of the brain. It is formed by the orbital plates of the frontal, the cribriform plate of the ethmoid, and the small wings and fr ...

Structure

The posterior ethmoidal nerve is a branch of the

, itself a branch of the

ophthalmic nerve The ophthalmic nerve (V1) is a sensory nerve of the face. It is one of three divisions of the trigeminal nerve (CN V). It has three branches that provide sensory innervation to the eye, the skin of the upper face, and the skin of the anterior sc ...

(CN V₁), itself a branch of the

trigeminal nerve In neuroanatomy, the trigeminal nerve ( lit. ''triplet'' nerve), also known as the fifth cranial nerve, cranial nerve V, or simply CN V, is a cranial nerve responsible for sensation in the face and motor functions such as biting and che ...

(CN V). It passes through the posterior ethmoidal foramen, with the posterior ethmoidal artery. It gives branches to the sphenoid sinus and the ethmoid sinus. It also gives a branch to supply part of the

in the

Variation

The posterior ethmoidal nerve is absent in a significant proportion of people. This may be around 30%.

Function

The posterior ethmoidal nerve supplies sensation to the sphenoid sinus and the ethmoid sinus. It also supplies sensation to part of the

in the

Other animals

The posterior ethmoidal nerve is present in other animals, including

horses The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 million ...

. Headshaking can sometimes be treated with

analgesia Pain management is an aspect of medicine and health care involving relief of pain (pain relief, analgesia, pain control) in various dimensions, from acute and simple to chronic and challenging. Most physicians and other health professional ...

or neurectomy of the posterior ethmoidal nerve.

Reference

External links

* * () * http://www.dartmouth.edu/~humananatomy/figures/chapter_45/45-6.HTM {{Authority control Ophthalmic nerve