Posterior ethmoidal artery

The posterior ethmoidal artery, smaller than the anterior ethmoidal artery, branches off from the ophthalmic artery when it reaches the medial wall of the orbit. It passes between the upper border of the medial rectus muscle and superior oblique muscle to pass through the posterior ethmoidal canal, to supply posterior ethmoidal cells, and, entering the cranium, gives off a meningeal branch to the dura mater, and nasal branches which descend into the nasal cavity through apertures in the cribriform plate, anastomosing with branches of the sphenopalatine.

This artery supplies the posterior ethmoidal air sinuses, dura of the anterior cranial fossa, and the upper part of the nasal mucosa.