Structure
The anterior ethmoidal nerve is a branch of the nasociliary nerve, which is itself a branch of the ophthalmic nerve (part of the trigeminal nerve). It arises from the nasociliary nerve within the orbit (the bony cavity that houses the eye) and passes through the ethmoidal foramen, a small hole in the ethmoid bone located between the orbits.
Location
The anterior ethmoidal nerve is located within the skull, specifically within the orbit and the ethmoidal sinuses (air-filled cavities within the ethmoid bone). It exits the skull through the ethmoidal foramen and enters the nasal cavity, where it divides into branches that supply the anterior (front) portion of the ethmoidal sinuses and the mucous membranes of the nasal cavity.
Function
The anterior ethmoidal nerve provides sensory innervation to the mucous membranes of the anterior ethmoidal sinuses and the nasal cavity. This includes the sense of smell and the sensation of touch, temperature, and pain in these areas.
Clinical significance
Damage to the anterior ethmoidal nerve can result in decreased or loss of sensation in the anterior ethmoidal sinuses and nasal cavity, as well as impaired sense of smell. This can be caused by trauma, infection, or surgery involving the nasal cavity or orbits. In some cases, injury to the anterior ethmoidal nerve can also result in epistaxis (nosebleeds) due to damage to the blood vessels in the nasal cavity
