Anterior ethmoidal nerve

The anterior ethmoidal nerve is a nerve which provides sensory branches to the nasal cavity.[1] The nerve is the continuation of the nasociliary nerve after it enters the anterior ethmoidal foramen into the anterior ethmoidal air cells. The nasociliary nerve arises from the Ophthalmic division of the Trigeminal nerve (CN V) within the orbit. The anterior ethmoidal nerve arises only after the nasociliary has given off its four branches - 1) Ramus communicans to ciliary ganglion, 2) Long ciliary nerves, 3) infratrochlear nerve, 4) Posterior ethmoidal nerve.

Anterior ethmoidal nerve
The ophthalmic artery and its branches. (Nerve not pictured, but location is similar to artery.)
Details
From	nasociliary nerve
Identifiers
Latin	nervus ethmoidalis anterior
TA	A14.2.01.030
FMA	52675
Anatomical terms of neuroanatomy

After branching off of the nasociliary nerve, the anterior ethmoidal nerve enters the anterior ethmoidal foramen and send sensory fibers to the middle and anterior ethmoidal air cells. The anterior ethmoidal nerve then continues into the cranial cavity at the side of the cribiform plate of the ethmoid bone, sends sensory fibers to the meninges, and then enters the nasal cavity via the nasal slit. Within the nose, this nerve gives off sensory fibers to the anterior part of the nasal septum[2]

The branches it gives rise to are called the internal/septal and external nasal branches of the anterior ethmoidal nerve, and the external branch ultimately innervates skin on the lateral sides of the nose.