Anterior Ethmoidal Nerve, Inferior View

Description

Arising from the nasociliary nerve (ophthalmic division of the trigeminal nerve), the anterior ethmoidal nerve tracks anteromedially along the orbital roof before passing through the anterior ethmoidal foramen with the anterior ethmoidal artery. From an inferior (ventral) cranial base perspective, its course is appreciated as it transitions from the orbit into the anterior cranial fossa, then descends toward the nasal cavity through the cribriform region of the ethmoid. Nearby, other cranial nerves appear in yellow and the major arteries and veins of the ventral brain surface are color coded in red and blue, framing the nerve’s small caliber against larger neurovascular landmarks. Orientation is anchored by the paired temporal lobes laterally and the frontal lobe more superiorly in the field. This is a high-yield pathway because the anterior ethmoidal nerve is the main sensory supply to the anterosuperior nasal septum and lateral nasal wall, and its terminal external nasal branch innervates the dorsum and tip of the nose. Surgeons operating endoscopically near the frontal recess, ethmoid roof, or cribriform plate watch this structure closely, since injury at the anterior ethmoidal canal can accompany anterior ethmoidal artery bleeding and predispose to cerebrospinal fluid leak when the skull base is violated. It is also a practical correlate for anterior septal pain syndromes and referred nasal pain patterns. Use this illustration in skull base anatomy teaching, ENT endoscopic sinus surgery atlases, or neurosurgical approaches to the anterior cranial fossa where the orbit, ethmoid, and ventral brain relationships must be kept straight in one glance. It also fits well in board-style cranial nerve reviews that contrast V1 branches and their foramina. Anatomical accuracy verified by SciePro's Medical Advisory Board.