Corpus: Anterior ethmoidal nerve

The anterior ethmoidal nerve is a branch of the nasociliary nerve that travels through the anterior ethmoidal foramen from the orbit into the cranial cavity.

Upon re-entering the cranial cavity, the anterior ethmoidal nerve traverses a shallow bony depression along the lateral edge of the cribriform plate of the ethmoid bone. It then passes through a slit beside the crista galli into the nasal cavity, where it releases fibers that innervate the nasal mucosa of the frontal part of the nasal septum and the lateral wall of the nasal cavity. Finally, it emerges as the ramus nasalis externus between the lower edge of the nasal bone and the lateral nasal cartilage.

The anterior ethmoidal nerve provides sensory innervation to the aforementioned regions of the nasal mucosa, as well as the skin of the nostrils and the tip of the nose.