Quick Facts
Origin: Nasociliary nerve.
Course: Runs medially through the anterior ethmoidal foramen into the anterior and middle ethmoid air cells, with fibers continuing medially into the superior nasal cavity.
Branches: Lateral and medial internal nasal branches and external nasal branches.
Supply: Conveys general sensation from the mucosa of the anterior and middle ethmoid air cells, the mucosa of the superior and anterior surfaces of both the nasal septum and lateral wall, and the skin of the dorsum, ala, and apex of the nose.
Related parts of the anatomy
Origin
The anterior ethmoidal nerve is a branch of the nasociliary nerve.
Course
From its origin, the anterior ethmoidal nerve runs medially to the anterior ethmoidal foramen, located lateral to the groove for the olfactory tract. It enters the anterior and middle ethmoid air cells and continues medially to reach the superior surfaces of the lateral wall and septum of the nasal cavity.
Branches
The anterior ethmoidal nerve gives rise to the lateral and medial internal nasal nerves. It also gives rise to the external nasal branches, either directly from the anterior ethmoidal nerve itself, or indirectly via the lateral internal nasal nerves.
Supplied Structures
The anterior ethmoidal nerve is a sensory nerve that conveys general sensation from the mucosa of the anterior and middle ethmoid air cells.
After entering the nasal cavity, the medial internal nasal nerve conveys sensation from the superior and anterior nasal septum. The lateral internal nasal nerve conveys sensation from the mucosa of the superior and anterior lateral wall of the nasal cavity.
The external nasal branches of the anterior ethmoidal nerve leave the nasal cavity, becoming cutaneous just inferior to the nasal bone. These branches convey sensation from the skin of the dorsum, ala, and apex of the nose.
